Revisiting Roman Statehood: Examining the International Legal Framework of the Foederatio Model in the Context of the Later Roman Empire

Viktor Melnyk
Department of Political Science, Faculty of Philosophy, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine 
Correspondence to: Viktor Melnyk, melnyk.v@ujis.in.ua

DOI: https://doi.org/10.70389/PJS.100234

Additional information

• Ethical approval: N/a
• Consent: N/a
• Funding: No industry funding
• Conflicts of interest: N/a
• Author contribution: Viktor Melnyk – Conceptualization, Writing – original draft, review and editing
• Guarantor: Viktor Melnyk
• Provenance and peer-review: Unsolicited and externally peer-reviewed
• Data availability statement: N/a

Keywords: Lex foedus, Asymmetric federalism, Jurisdictional stratigraphy, Christianitas legitimation, Foederati patron-client relations.

Peer Review
Received: 14 November 2025
Last revised: 16 December 2025
Accepted: 17 December 2025
Version accepted: 3
Published: 31 January 2026

Plain Language Summary Infographic

Highlights

• The article interprets the Roman Empire of the Dominate as a quasi-federative foederatio: lex foedus worked as an internal–external legal “bridge” between ius civile and ius gentium, creating asymmetric federalism, jurisdictional stratigraphy and conditional integration of barbarian communities via modified patron–client ties.
• The division into “East” and “West” (364 and 395) is argued not as a breakup into two sovereign states but as an administrative-functional decomposition of a single legal subject; Byzantium is treated as the continuing Roman Empire whose legal personality and hegemony survived the fall of the Western segment.
• Foederati are shown as hybrid actors under lex foedus: formally subordinated protectors and buffer zones, yet progressively militarised and autonomised, which both stabilised frontiers and, in the long run, eroded centralised imperial control and encouraged polycentric fragmentation.
• The study links Roman international legal personality to Christianitas and the idea of “divine election”: the Empire is conceptualised as a sacralised, universal federative organism (oikoumene) that incorporates provinces, colonies, vassal regna and barbarian polities into a single, Christian-legitimised legal and ideological space, influencing later European federative models.

Introduction

This article explores the constitutional development process of the Roman Empire in the Dominate (284–476 CE) in terms of international law theory, in particular (1) How lex foedus operated as a mediating practice in the relationship between legal hierarchy within Rome (ius civile, ius publicum) and legal practice indicating the establishment of treaties with foreign states (ius gentium, ius fetiale)? (2) Does the late Roman Governmental system qualify as a kind of quasi-federation foederatio where the local units had independent, but subservient legal personality? (3) What were the consequences of Christianization of imperial ideology (especially the notion of Christianitas as universal divine election) on the legal system of Roman sovereignty and its interaction with foederati peoples?

These inquiries fill an important blank in Romano-Byzantine juristic knowledge. Although the administrative reformation of Diocletian, Constantine, and Theodosius,^1–3 and the military-strategic position of foederati peoples,^4,5 have been well documented in the literature, fewer studies have incorporated these two phenomena into a single theory of Roman international legal personality. In imagining the Dominate-era Empire as a foederatio (polity based on hierarchical legal pluralism, as opposed to modern federal equality), this article is a contribution to the current discussion of how late antique sovereignty and how the juridical framework of imperial integration works, and whether its continuity into the Byzantine polity is evident.^6,7

In this analysis, quasi-federatio is used to designate a form of governance in which the supreme imperial power(imperium) retained ultimate sovereignty, but allowed the subordinate units to have varying levels of autonomy through formalized (that is, expressly stated in writing) treaties (foedera).^4,8 As a term of anachrony, international legal personality describes how the Roman state governed its multi-tiered system of juridical integration. The topicality of this question is not just an antiquarian interest. The way that the study addresses the problem of asymmetric sovereignty, legal pluralism and how non-state formations were recognized and incorporated into overriding normative structures provides a historical analogy of how cultural universalism and legal particularism interact in the present-day imperial and post-imperial setting.^4,5 Besides, the concern with managing the relationship between foederati in the study finds historical parallels in the way that Rome managed to control the relationship between foederati and its system of law.^8–10

Diocletian’s administrative and territorial reorganisation established a federalist structure within the Roman Empire. This framework was built to ensure regional autonomy for the tetrarchy while integrating it into a complex system of interaction between the centre and the periphery.^{1(p. 78)} The structural differentiation of prefectures and dioceses, which was further refined through the administrative innovations of Galerius (305–311) and Constantine the Great (306–337), laid the foundation for unifying imperial governance.² The tetrarchic mechanism, organised around the symbiotic coexistence of two senior emperors (Augusti) and two junior co-rulers (Caesars), represented a politico-legal model of territorial subordination aimed at preserving state integrity by coordinating decentralised elements.^{11(p. 23)} Despite the transition to a personalised imperial dominion under Constantine the Great from 324 to 337, the formal legal status of the Empire remained rooted in the principles of tetrarchic regulation.^{3(p. 54)}

The reform act of 364, by the co-emperors Valentinian I (364–375) and Valens (364–378) standardised the legal aspects of the relationships between the “Praetorian Prefectures” and “Dioceses” as substructural units of administrative division.^{12(p. 847)} While stationed in Constantinople, the emperors involved the senatorial corps as the supreme legislative body to formalise the division of the Empire into the jurisdictionally distinct zones of “East” and “West,” which were established as equivalent regional segments of their dyarchic rule.^{13(p. 89)} Simultaneously, they mutually proclaimed parity in their authoritative status, supported by official proclamations affirming “equal” rank.^{14(p. 4)} The territorial division into “East” and “West” functioned purely as an administrative decomposition, maintaining the universal validity of each emperor’s decisions across the imperial domain. The legal innovations implemented within this reform drew on the legislative framework of the “dyarchy of West and East” conceptualised during Diocletian’s era. These innovations underscored the administrative and legal system’s advanced legal evolution and syncretism, emphasising state integrity through jurisdictional pluralism.

The administrative arrangements formalized in 395, issued during the reign of Theodosius the Great (379–395), did not serve as an autonomous regulatory corpus but rather represented a formalised verification of earlier reform initiatives associated with Valentinian and Valens. It is noteworthy that Valentinian concluded his tenure amid the finalisation of a peace treaty with the Quadi,^{15(p. 901)} while Valens was defeated and killed by the Visigoths in the tragic climax of the Battle of Adrianople.^{16(p. 16)} Despite destabilising trends, Theodosius I demonstrated exceptional competence in strategic manoeuvres, neutralising Gothic uprisings.^{17(p. 27)} and restoring the Danubian limes along its right bank.¹⁸ However, the Rhine limes, which had become a hub for barbarian ethnic groups such as the Vandals, Suebi, and Burgundians, faced increasing challenges due to the continuous aggression of Hunnic cavalry formations. The multifaceted nature of external threats called into question the feasibility of effective centralised administration, highlighting the imperative need for imperial presence at multiple key theatres of potential military escalation, exposing the latent dysfunctionality of the administrative system under extensive geopolitical pressure.

By the final years of the fourth century, the political-administrative concept of “federation” had collapsed entirely, losing its viability as a mechanism for geostrategic containment of barbarian ethnocentric conglomerates. Under existential pressure from aggressive Hunnic formations,^19(p. 21) these groups breached the fortified imperial limes and invaded peripheral yet strategically significant provinces. This cascade of destructive events catalysed the formation of a new military-strategic paradigm, necessitating the emperor’s presence at the epicentre of any breach. This increased the dynamic responsiveness of imperial authority to external threats. In response to the geopolitical degradation, Theodosius I’s sons, Honorius (395–423) and Arcadius (395–408), were delegated to govern the Western and Eastern segments of the imperial domain, respectively, optimising their adaptive capacity to respond to barbarian invasions. Before ratifying a key edict, Theodosius I, holding monocratic authority over the integrated imperial polity, concluded that institutionalised fragmentation of imperial magistracy was necessary. This decision, driven by organisational pragmatism and the extraordinary challenges of the era, laid the groundwork for a fundamental transformation of the imperial power structure.

The dualistic division of administrative-political competence reflected not only pragmatic adaptation to external aggression but also the evolution of the Roman state apparatus, strained by overextended territorial scale, systemic socio-economic entropy, and internal political dysfunction. These factors converged into a new governance model seeking to balance centralised monarchical power with regional autonomy.

From 364 onward, and not exclusively from 395, the Roman Empire operated as an integrated state megastructure divided administratively between eastern (Imperium Romanum Pars Orientale) and western (Imperium Romanum Pars Occidentale) substructures.^13(p. 85) These substructures, denoted as parties, did not acquire the status of sovereign political entities but were conceptualised as synthesised aggregations of provinces within which emperors exercised immediate and concentrated governance in military, political, and jurisdictional spheres.^20(p. 46) The normative innovations of 364 and 395 demonstrated their teleological and constructive justification, as by 480, the continuity of the Roman state was preserved through the institutional stability of the eastern imperial segment.^{21(p. 90)} The exclusive thesis posits that the eastern segment of the Roman Empire, retrospectively identified as “Byzantium” in modern historiography, assumed legal supremacy and acknowledged dominance over all barbarian political entities that emerged from the fragments of the western portion of the Empire following the catastrophic breach of the Rhine limes on December 31, 406.^{22(p. 23)} The de jure legitimisation of the hegemony of the eastern segment, known as Byzantine, was possible only because the Roman Empire, despite the binary administrative division introduced by the reforms of 364 and 395, remained perceived by the intellectual elites of the legal and philosophical discourse of the time as a unified, indivisible legal entity serving as the integrator of civilisational order.

Literature Review

A constellation of researchers has conducted a meticulous and analytically determined examination of the interplay between the concept of lex foedus, regarded as a jurisdictional modality of Roman ius publicum (public law), and the processes of identity representation in the statehood of Imperial Rome during the Dominant period. Within this discursive paradigm, M. Canepa, in his refined work “The Iranian Expanse: Transforming Royal Identity Through Architecture, Landscape, and the Built Environment,” highlights the interaction of pre-Islamic Middle Eastern dynasties with cultural-ideological memorials and sacral-urbanistic structures that served as semiotic agents legitimising power. These dynasties, through syncretic consolidation with tribal ethnic formations, established multifaceted political connections, which formed the foundation for developing and iteratively implementing innovative governance mechanisms and dominant strategies.

Canepa underscores the royal discourse as a systematically organised phenomenological construct embodying multilayered ideological narratives and serving as the basis for political architectonics and symbolic hegemony.^{23(p. 23)} The work by Canepa determines how the imperial authority was justified by the architectural and symbolic schemes in the culturally different areas which give important links to the material manifestations of the sovereignty.^21,22 But his attention to pre-Islamic Iran prevents any proper attention to the means by which, with legal hierarchies in place, Rome incorporated barbarian polities through the use of juridical means to which far less attention was given, namely treaty law and lex foedus. The current paper is the expansion of the symbolic analysis offered by Canepa to consider how the asymmetrical relationships articulated by architecture and ritual were formalized by legal tools (foedera). Nevertheless, relatively little is known about the very juridical processes through which foedus agreements granted some legal personality and foederati a place in the rankings between ius gentium and ius civile.^4,24

José Luís Brandão, in his monograph “Confronting Identities in the Roman Empire: Assumptions about the Other in Literary Evidence”, emphasises that the category of foederatio functioned as a kind of metaphysical oscillation between immanent integration and transcendent otherness. In the literary tradition of the Dominate period, foederati emerged as a discursive construct which, while being a legal phenomenon, simultaneously encapsulated the semantic tension between the centripetal impulses of imperial universality and the centrifugal manifestations of peripheral autarky. Brandão perceives foederatio not merely as a juridical mechanism but as a cultural paradigm that facilitated the retransmission of hierarchical ideals, wherein barbarian subjectivity was acknowledged only within the framework of regulated subordination.

Thus, the foederati served as symbols of political ambivalence, legitimising imperial hegemony while granting recognition to the identity of the “Other” within the context of the Roman civilisational project.^{23(pp. 47–48)} The literary-cultural approach by Brandao throws some light on the discursive aspects of foederati identity, by showing that foederatio is a category of law as well as a cultural production.²³ But his commentary is purely on the plane of presentation as opposed to the plane of the law. Missing is a methodical description of how foedus agreements as legal devices which are independent of literary topoi actually granted limited legal personhood, defined rights and liability, and placed foederati on the pyramid of ius gentium versus ius civile.^4,24 The research is a supplement to Brandao, as it examines the legal concrete architecture through which the described cultural representations take place.

The present study therefore supplements the cultural analysis provided by Brandao by analytically looking at the functioning of foedus treaties as legal instruments of giving rights, duties and levels of sovereignty.^4,24 In his comprehensive study “The Roman Empire and the Legal Status of the Visigoths: The Context of the Lower Danube War of 365–369,” researcher V. Melnyk offers an exhaustive discourse aimed at deeply understanding the diplomatic protocols that constituted the quintessence of political architectonics and state-building processes during a period of intense geopolitical perturbations. Emperor Valens, demonstrating exceptional acumen in macropolitical manoeuvring, did not confine himself to ratifying formal peace treaties but sought to conceptualise transcendent strategies that promoted long-term political consolidation between discrete subjects of international law.

Within this research, the author focuses on the exclusive experience of Rome’s interactions with the sociopolitical conglomerates of Eastern Europe, characterised by politico-economic fragmentation and asymmetrical diplomatic models. An integral analysis of politico-economic dispositions played a pivotal role in shaping strategic matrices and regulating the dynamics of diplomatic interactions. The author also emphasises the importance of a phenomenological approach to assessing socio-cultural volatility, which determines the specificity of decision-making by political agents. This comprehensive methodology catalysed the development of adaptive and highly institutionalised models of political interaction, laying the foundation for stabilising geopolitical equilibrium amidst chronotopic transformations.^{25(p. 1)}

The case study of Valens and Visigoths given by Melnyk gives some useful details regarding a particular diplomatic episode and its strategic background.²⁵ His emphasis on one emperor-barbarian dyad, however, does not answer the more general question whether the treaty system of Rome was a systematic legal system of administering a multi-tiered polity. There is no consideration of the relation of individual foedera to the constitutional form of the empire on the whole, and especially the administrative reforms of 364 and 395 which partitioned the empire into eastern and western partes.^13,14 It is in this context that this article places specific treaties within the broader federative framework where foedus practices and internal administrative divisions were considered to be based on a single logic of stratified sovereignty. In particular, this article states that the 364 and 395 administrative reforms represented the same federal logic that foedus treaty practices had already internalized.^4,13,14,20

In his monumental work “The Roman Empire in Late Antiquity: A Political and Military History,” esteemed researcher H. Elton focuses on the profound politico-administrative metamorphoses accompanying the culminating stages of institutional transformations during the terminal phase of the Roman Empire’s existence. The scholar highlights that, despite the poly-crisis nature of the third-century cataclysms, Christian orthodoxy exhibited remarkable adaptive flexibility and expansionist potential, as evidenced by the functioning of conciliar assemblies, which served as platforms for doctrinal systematisation and sacred legitimisation. Elton accentuates the paradigmatic shift in the interaction between the imperial power hierarchy and subaltern social groups: integrating public discourse into proto-democratic institutions created opportunities for articulating collective narratives and forming socially acceptable feedback mechanisms.

Equally significant is his exegesis of administrative-territorial reforms, which initiated a radical reconfiguration of the functional parameters of regional magistracies and contributed to forming institutional prototypes of militarised structures, identifiable as embryonic forms of military policing.^26(p. 219) The history of the military and administration of Elton is a detailed account of the structural changes that took place in the late empire, such as the militarization of frontier administration and the incorporation of foederati into the defense of the empire.^4,26 What is not theorized in his explanation is the juridical ground of such arrangements: how did lex foedus serve as the juridical tool of the relationships between internal administrative superiority and external treaty-relations?

Moreover, Elton does not take administrative reforms (e.g., the divisions of 364 and 395) and foederati policies apart, without any attempt to determine whether they had a common federative logic.^4,13,14,20 This article maintains that the two phenomena represented a quasi-federative paradigm where subordinate politics (imperial partes or barbarian gentes) enjoyed delegated power in a broader legal framework. The juridical form of this quasi-federative model namely the manner in which lex foedus mediated internal administrative subordination and external treaty relations, need to be theorized in a systematic manner that is what the present study offers.

Eugene C. McQuade, in his comprehensive monograph “From Republic to Empire: The Roman Empire Explained: A Journey Through the Most Powerful Civilisation in History”, elucidates the intricate dialectics of transformational processes accompanying the transition of the Roman Republic to an imperial governance model. The author emphasises political reorganisation as the culmination of cumulative institutional mutations, synergistically blending pragmatic adaptability with ideological dogmatism. McQuade offers a refined analysis of axiomatic centralisation and its correlation with the implicit normativity of imperial order, articulated through jurisprudential homogenisation and the cultural imperative of assimilationist policy.

In his conceptualisation, the imperial project represents an ambivalent structure wherein the syncretism of ethnopolitical identities was subordinated to a sacral-political teleology, asserting the discursive primacy of the imperial centre over peripheral plurality.^{27(p. 17)} The synthesis developed by McQuade focuses on centralization and assimilation as the key characteristics of an imperial project.²⁷ However this interpretive frame can fail to recognize the extent to which the late Roman governance did agree to the legal pluralism and unequal autonomy. According to recent study on Roman law, the continuity of local legal traditions and stratified implementation of ius civile versus ius gentium^24,28 is emphasized. Furthermore, the history of Christianity, especially the ideology of Christianitas as divine election in the justification of hierarchical pluralism, over centralization, needs to be analyzed further.^8–10

This paper criticises excessively centralist interpretations by showing how the empire served as a federative framework that involved a variety of legal statuses into a sacral-political oikoumene. Specifically, the contribution of Christianitas ideology as a justification of hierarchical legal pluralism instead of the equal centralization has not been sufficiently theorized.^8–10 This study is described in this study where the discourse of divine election offered ideological framework of the asymmetric sovereignty in a federative imperial system. Although current literature has shed light on such crucial aspects of late Roman rule as the symbolism of architecture,²¹ cultural manifestations of foederati,²³ particular diplomatic events,²⁵ military-administrative formations,^4,26 and centralization discourses,²⁷ there are still notable gaps in the analogy. None of these elements has been systematically combined into one body of law systematizing lex foedus as the juridical form of relation and of hierarchical system that links internal hierarchy and external relation, or of examining whether the administrative reforms of 364 and 395 represented a federative logic already inscribed in the practice of treaties.^13,14,20

Also, the overlap of Christianitas ideology with legal pluralism the ways in which discourse of divine election justified asymmetric sovereignty is not thoroughly theorized yet.^8–10,29,30 None of the studies has introduced a systematic combination of administrative reforms, foederati practice, and Christian ideology into a single legalization and lex foedus used as the juridical engine between interior order and external relations. These gaps have been bridged by this article discussing how the Dominate-era Empire operated as a quasi-federative foederatio with stratified legal personality at several levels of jurisdiction.

The present study seeks to profoundly conceptualise the Roman Empire as a foederatio by analysing its international-legal ontology and delineating the constitutive elements of its legal subjectivity during the transformative Dominatus period. The research underscores the synthesis of normative-legal autonomy and the hegemonic extrapolation of imperial authority as a fundamental feature of the empire’s politico-legal architecture. Furthermore, it examines the transgressive politico-juridical identification mechanisms underpinning the empire’s international integration and structural homogenisation. These dynamics are interrogated through a hermeneutically grounded analysis of statehood archetypes, which informed the structural paradigms of governance and the stratified legal frameworks embodied within the imperium Romanum doctrine.

Research Methodology

The scientific analysis employed a multidimensional methodological arsenal, encompassing descriptive, analytic-synthetic, comparative, generalisation, chrono-typological, historical-comparative, and historical-systematising methods. The descriptive approach, oriented towards articulating the ontological characteristics of the period of dominant hegemony, contributed to establishing a systematic foundation for the subsequent epistemological interpretation of the specificities of historical transformations. The analytic-synthetic methodology enabled the conceptual decomposition of complex politico-legal phenomena of the Roman Empire, followed by their reconstruction into integrative theoretical constructs. The comparative method functioned as a correlation-analytical tool, establishing functional interconnections and structural parallels between the key determinants of the empire’s subjectivity, including its socio-economic and political components. The chrono-typological method, intrinsically aimed at identifying temporal markers and stratifying chronological periods, facilitated in-depth analysis of the temporal dynamics of the studied phenomena.

The historical-comparative approach focused on uncovering causal-deterministic interdependencies that were the foundation for consolidating ethno-national identity and integrating the empire’s peoples. The historical-systematising method ensured the construction of a consistent, logically verified reconstruction of events. At the same time, the generalisation approach played an integrative role, synthesising the obtained results during the final theoretical consolidation phase.

Research Results

Drawing on the theoretical-legal methodology, an in-depth discursive examination of the legal regime of lex foedus as an imperative foundation of Roman public-law federalism establishes the ontological basis for extrapolating jurisdictional-legal and administrative-institutional mechanisms that constituted the architecture of the structural-state dualism represented as the “Western Roman Empire” and the “Eastern Roman Empire.” Despite the precedent-setting incorporation of the lex foedus legal regime into the realm of imperial norm-making and its application by Roman emperors to barbarian polities across the European subcontinent, North African geopolitical cluster, Caucasus region, and Near Eastern macro-region, its specific juridical modality facilitates the conceptualisation of a federalist governance paradigm within the framework of imperial administrative-territorial stratification. It also reveals inherent features of administrative jurisdiction applied to various levels of the governance system—from provinces to polis formations.^{31(p. 209)}

The increasing centralization of imperial authority during the dominant period determined the absolutist unitarisation of legal disposition, resulting in the irreversible juridical erosion of any relics of consociative federalism. The institutionalisation of sacralised autocratism correlated with the dynamics of the desubstantiation of traditional politico-administrative modalities that had previously functioned within the framework of latent polycentricity. In this context, the categorical imperative of imperium sine limitatione postulated the necessity of hypostatised jurisdictional transcendence, wherein any entity deprived of the status of state substance was automatically reduced to the legal accessory. The sovereign monomorphism of political architectonics precluded the genesis of alternative centres of juridical legitimation, transforming peripheral entities into integral derivatives of imperial ontology.

The legal integration processes of federative assimilation was grounded in the doctrinal exclusivity of auctoritas imperialis, which absorbed any remnants of political parity within the framework of a vassalage-determined structure of interrelations. The dispositive parameters of the legal subordination of allied entities were formulated through the prism of unified reception, where foedus iniquum served as the normative instrument of the final juridical depoliticisation of dependent subjects.^{6(p. 37)} The Codex Theodosianus codified these legal categories, establishing formal distinctions between foedus aequum and foedus iniquum that governed barbarian settlement rights and obligations.²⁴

The juridical monism of jus imperii rendered impossible the autonomous functioning of contractual constructs outside the paradigmatic matrix of imperial universalism, engendering a phenomenon of legal homogenisation that obliterated any traces of politico-juridical multiplicity. The internalisation of imperial nomocratism led to the complete elimination of alternative forms of international legal personality, ultimately consolidating the unitary character of the political organism of the Dominate (Table 1). As shown in Table 1 the quasi-federative structure of the Dominate was based on a three-legged system comprising: (1) formal federative political structure, with differentiated territorial units (tetrarchies, eastern/western partes), (2) stratified legal statuses of foederati (foedus aequum, foedus iniquum, clientela, deditio), and (3) an international legal personality doctrine, which placed the emperor in the position of final judge of all treaty relationships, acting by ius fetiale, ius gentium.^1,4,13,14,24

Table 1: Doctrinal postulates and structural-functional mechanisms of federation and international legal personality within the imperial paradigm of the Roman Dominate.
Categorical Imperatives of the Imperial Order	Ontological and Normative-Doctrinal Exegesis	Juridico-Institutional Implementational Constructs	Historical Examples
Federative Political Structure	The imperial policy of integrative consolidation was accompanied by a formalised stratification of subordinate entities, regulated by strict legal norms that excluded spontaneous autonomous initiatives. The dominant vector remained the gradual absorption of ethnopolitical units deprived of full sovereignty.	The legal institution of foedus aequum, the protectorate system of clientelae, and the centralised policy of subordinative legitimisation accompanied by the imperial redistribution of competences.	Tetrarchy (293–305 CE): four co-emperors governing distinct territorial zones;1,26 Administrative divisions of 364 and 395 CE creating eastern/western partes;8,9 Diocese system under Diocletian and Constantine.2,3
Legal Status of Foederati	The conceptual dichotomy between limited personal jus civitatis and subordination to jus imperii determined the specific nature of foederati’s legal relations with the centre. The complementarity of local norms with the general imperial legal framework eliminated the possibility of autonomous legal reception without the explicit sanction of the emperor.	Institutionalisation through lex foederata, normative stratification of privileges, limited jurisdictional sovereignty within jus gentium.	Gothic foedus of 382 CE after Adrianople;11,12 Frankish settlements in Gaul under Julian;20 Vandal foedus in Africa;20,25 Each treaty specified distinct rights (land grants, tax exemptions) and obligations (military service, recognition of imperial suzerainty).
Imperial International Legal Personality	The system of foreign relations was defined by principles of differentiated subordination, which made equal diplomatic interaction with external actors impossible. The formalisation of imperial supremacy on the international level was embodied through the doctrine of sacralised monarchical prerogative, which placed the emperor beyond the ordinary political and legal sphere.	Norms of jus fetiale, the mechanism of unconditional deditio, which entailed the absolute loss of subjectivity, the concept of auctoritas imperialis as an apodictic form of foreign policy domination.	Roman-Sasanian treaties of 298, 363, 387, 422 CE;31 Embassies and diplomatic protocols with Germanic kingdoms;19,20 Imperial claims to universal authority over all barbarian regna post-476.15,16
Doctrine of the Dominate	Institutional centralisation reached its apogee through the dismantling of residual republican mechanisms and the transformation of the political structure into a sacralised autocratic system. The concept of the emperor’s divinely preordained authority excluded the possibility of formal political dualism between the Senate and the monarch.	The absolutist concept of dominium, new administrative stratification of provinces that eradicated traditional forms of autonomous self-governance, and the dominance of praetorian legal regulations.	Diocletian’s adoption of divine epithets “Jovius” and “Herculius”;1,26 Constantine’s Christian imperial theology;2,4,32 Theodosius I’s enforcement of Nicene orthodoxy as state religion.13,32,33
Legalisation Policy Regarding Foederati	The normative regulation of imperial subjecthood was carried out through codification acts that gradually incorporated peripheral territorial entities into a centralised system of legal dominance. The homogenisation of legal relations enabled the elimination of institutional differentiation between entities with different historical and legal statuses.	Lex Antoniniana, the gradual extension of civil law to subordinate territories, the doctrinal conceptualisation of subjecthood as an inescapable condition of legal existence.	Constitutio Antoniniana (212 CE): Caracalla grants citizenship to all free inhabitants of empire;6,7 Gradual extension of Roman law to provincial territories under Diocletian and Constantine;1–3 Legal integration of foederati communities: Gothic law codes influenced by Roman jurisprudence;6,25 Codex Theodosianus (438 CE) regulating status of foederati and barbarians within empire.6
Forms of Vassal Dependency	The regulated integration of allied polities was implemented through multi-tiered mechanisms that ensured the gradual degradation of their international subjectivity within the imperial legal framework. The multi-level gradation of vassal dependence provided multiple options for subjugation, depending on the degree of political assimilation.	Treaties of the tractatus type, the legal instrument of modus vivendi, status obsequialis, which signified political protection without autonomy, and foedus iniquum, which established the dominant position of the imperial centre.	Foedus iniquum examples: Vandal treaty 442 CE recognizing imperial supremacy;20,25 Tractatus agreements with Germanic tribes along Rhine frontier;14,20 Status obsequialis: client kingdoms of Armenia and Lazica vis-à-vis Rome and Persia;30,31 Modus vivendi arrangements with Frankish chiefs under Julian and Valentinian;14,20 Gothic treaty 382 CE as foedus iniquum despite initial Roman military defeat.11,12,19
Source: Synthesized from Waldron,1 Drijvers,13 Melnyk,14 Grant,20 Stickler,4 Ibbetson,24 Rees,32 and Dari-Mattiacci and Kehoe.28

This Table 1 generalizes the constitutional organization of late Roman government, representing the map of how the doctrinal requirements (Column 1) were applied to concrete legal norms and institutions (Columns 2–3) with a real life example (Column 4) of an application of each of these principles. The framework shows the quasi-federative pattern where subordinate groups, either imperial partes or foederati polities, had delegated power within a larger hierarchical legal framework.

A fundamental epistemological reflection on lex foedus as an institutional construct opens avenues for the legal hermeneutics of the federal substance of the Roman Empire, thereby forming a methodological framework for legitimising the thesis on the federal determination of the administrative-territorial bifurcation of imperial space conventionally stratified into Eastern and Western segments.^{20(p. 13)} Within the context of a retrospective analysis of Rome’s international legal subjectivity, lex foedus not only plays a conceptual-structural role in chronologically legitimising the imperial politico-legal identity in relations with barbarian polities.^{4(p. 500)} but also serves as the ontological foundation for the epistemological justification of the categorical framework of political and legal subjectivity for the civilisational realms of the “East” and “West.”

An essential dimension in characterising federal systemicity and related international legal subjectivity is integrating the doctrine of Pax Christiana into the normative-legal matrix of the Roman Empire. Incorporating this conceptual singularity unequivocally demonstrates that the Christian discourse functioned as a constructive integrative factor in implementing state-federal prerogatives rather than as a destructive mechanism inducing structural disintegration.^{34(p. 129)} While it is traditionally posited that the sacral-epistemological paradigm of Christianity contributed to the disintegration of the Roman polity, contemporary epistemological analysis suggests the opposite: the process of Christianization stimulated the Empire’s public law, providing an ideological impetus to consolidate regional substructures and ethno-political constellations.

During the period when the Christian cult had not yet acquired codified legal status, the Roman Empire, immersed in the politico-economic crisis simulacrum of the 3rd century CE, exhibited a significantly higher probability of structural collapse compared to the post-legal sanctioning phase of Christianity (after 380 CE). Incorporating barbarian ethnic ensembles into the framework of the imperial jurisdictional space would have been exceedingly challenging without the cognitive-ideological resonance concentrated in the universal paradigm of the Christian oikouménē. Consequently, it is observed that the sacral discourse of Christianity performed an integrative function that fundamentally contrasted with destructive processes, ensuring the prolongation of the existential resource of the Roman imperial mechanism even after events historically marked as the “Odoacer Revolution” of 476 CE.^{26(p. 219)} By the late 5th century, the normative-legal paradigm decisively dominated political reality, synthesising traditional and contemporary institutional configurations.

The chronological span of imperial dominance, initiated during the reign of Diocletian (284–305) and prolonged for the Western Roman provinces until the institutionalisation of barbarian “regalia” over the unified imperial jurisdiction of the Eastern Roman Empire (476–480 CE), is exceptionally distinguished in the discourse of historical-legal evolution by its manifestation of the interplay between sociopolitical doctrines and normative-legal dispositives of public law, which assumed formal exegetical codification.^{32(p. 218)} Within this period, the sociopolitical actors of the Roman Empire, despite the prevailing trend of adopting Christian worldviews, retained a conceptual loyalty to the archaic paradigm of “oecumenism,” functioning as an integrative ideological matrix of a universal state order.^{6(p. 432)} The legal self-consciousness of both Eastern and Western Romans did not succumb to an essential cultural-territorial dichotomy, thereby enabling them to conceptualise their surroundings within the categorical framework of sui iuris – as an object of personified possession or potential expansive jurisdiction^{.20(p. 46)}

The constitutive paradigm of self-identification among Roman subjects, who interpreted their existence as a reflection of being “God’s chosen people,” mirrored integrative processes of intergroup synergy that fundamentally refuted the possibility of separatist isolation among intrasocial circles. The sociological phenomenon of the “Empire as a Commonwealth,” originating in the early Principate, was incorporated into the multidimensional archetypal behavioural models of Roman society during its period of hegemony, underscoring deeply rooted ideological cohesion. The dynamic development of dominant institutional innovations reached its zenith with Caracalla’s Edict of 212 CE, which conferred Roman citizenship upon every free individual of the Empire. This process not only resulted in the expansive broadening of the tax base but also fostered an exceptionally high level of loyalty among provincial communities and tribal elites, ensuring their retention within shared borders even during the crisis period of 235–270 CE.^{33(p. 230)}

The indisputable parameters coalition unity included the monarchical institution of the supreme ruler (the emperor), a consolidated religious doctrine (Christianity), and a unified civic status (Roman), which synergistically integrated with the traditions of harmonious unity within the Mediterranean market– an autonomous platform for trade operations, economic integration, and cultural-information exchange.

In the context of analysing the discourse surrounding the Christian conceptualisation of the Roman Empire’s “chosenness,” it is pertinent to emphasise that any identity is constituted through the lens of the binary opposition of “self” and “other,” a foundational axiom of identity paradigms. In contemporary scholarly discourse, this issue is predominantly represented within the frameworks of sociological and, primarily, ethnological exegesis. However, the dichotomy of amicus–hostis retains critical epistemological and ontological significance in the sociology of law and the theory of state and law, particularly in analysing the socially determined genesis of legal consciousness. It is irrefutable that the integration of the Christian doxological narrative, alongside the continued adherence to “oecumenist” dispositions, should be interpreted as an expression of collective psychosocial archetypal structures.

The juxtaposition of the “self” with a concretised or abstract “other” constitutes the epistemological foundation of any identity. The antinomic correlation between the “benevolent” and “malignant” phenomena a priori structures the discourse of identification. As previously noted, the imperial identity of the Roman Empire was characterised by a unique dialectical nature, as the Romans represented their Empire as a sui generis “ideal” political formation (“Republic”). Iran was undoubtedly the primary axiogenic impulse in subjectivising the Roman Empire through the opposition paradigm. This dichotomous opposition of “us vs. them” was deeply embedded in the context of the expansionist interventions of Alexander the Great between 332 and 323 BCE and the practices of Hellenistic hegemony over Western Asia.^{35(p. 209)}

The geostrategic expansion into Iran, reaching as far as the Indus River basin, remained a persistent focus of sociopolitical antagonisms and politico-ideological dispositions within the Roman Empire. Iran was not only a conceptualised and permanent military-strategic antagonist within the framework of imperial domination discourses but also a key actor in transregional economic intermediation. It played an essential axiological intermediary role within the transcontinental trade and economic matrices connecting the Roman Empire with geopolitical clusters of the Far East. Furthermore, Iran functioned as an eschatological pole of civilisational opposition, competing with Constantine the Great and other imperial actors in the sacralised topology of discursive struggles for the prerogative of “patronage” over Christian congregations in the Middle Eastern region.^{36(p. 31)}

In this context, with complete epistemological validity and ontological relevance, the relational dynamics between Iran and Rome served as a fundamental mechanism for the autopoietic constitution and self-representation of the Roman imperial archetype. Thus, exclusively interstate normative provisions can provide jurisprudence with a correctly epistemologically verified foundation for conducting multi-level comparative legal hermeneutic interpretations.

The politico-legal identity of the Empire, articulately manifested in the provisions of its diplomatic concordats with Iranian monarchs, demonstrates an unwavering adherence to the concept of historical territorial law. In its axiological dimension, this is determined by the Iranian doctrine of state substantiality, appropriated through the prism of sacralised dynastic continuity. The genetic matrix of this concept is localised in Greater Iran, where it achieved acmeological verification in the context of the political-legal expansion and structural stabilisation of the Sasanian dynasty’s state mechanism. Subsequently, it underwent a vectorial transplantation into the Mediterranean normative paradigm.^{22(p. 43)}

The Iranian reception of statehood represents a hypertrophied syncretisation of political legitimation with an inherent dynastic principle, positing an almost identical ontological identification of Iran’s geopolitical construct with the personalist power stratification of the Shahanshah and his patrimonial entourage. In counterpoint, the Roman concept of power exhibited an inversive nature rooted in republican institutionalism, where imperial jurisdiction was articulately determined through a democratic elective principle. Each diplomatic dispositive of the Roman establishment assumed a legal representation of power through the formula of the “Roman people,” who nominally delegated their prerogatives to the Senate. Emperors, exercising volitional acts of governance, operated either autonomously or through instrumental mediations by legates but continuously within the bounds of a regulated concordance with the senatorial curia.^{24(p. 30)}

The Edict of 311, normatively sanctioned by Emperor Galerius (305–311), institutionalised an epochal paradigmatic transformation of the confessional architecture of the Roman Empire, determining the progressive sacralisation of its politico-legal discourse. Rather than the Edict of Milan in 313, which Constantine I and Licinius Licinianus jurisdictionally ratified, this document set a precedent for the legal legitimation of Christian ecclesiae (church corporations) within the framework of Roman statehood. It established a conceptual ontological substrate for their further integration into the state’s normative architecture.^{34(p. 21)}

During the period when Emperor Constantine the Great embraced the transcendent synergy of the Christian worldview as a fundamental metanarrative paradigm capable of ensuring the ideological and political codification of the empire, the concept of Christianitas transformed into a multifaceted legal and sacral-institutional reality. Its official articulation occurred within the framework of the First Ecumenical Council held in Nicaea in 325.^{8(p. 200)} In the context of this civilisational shift, the geopolitical centre of the empire was reimagined, prompting the relocation of the administrative core from the ancient locus of Rome to a new urban site. Between 324 and 330, a monumental project was realised, culminating in the consecration on May 11, 330, which marked the genesis of a metropolitan agglomeration later named “Constantinople”.^{37(p. 355)}

Post-council canonical decretals, formulated based on Nicene resolutions, semantically recodified the Italian Rome designated “Old Rome.”^{29(p. 112)} Textual analysis of sources and reconstruction of the political-administrative logistics reveal that a new Senate was established in Constantinople, evolving into an integral political-administrative centre.^{30(p. 130)} This development created a dual senatorial system, with both Constantinople and Rome maintaining senatorial institutions within the unified imperial framework. Chronologically, starting from 364, the emperors of the western part of the empire, guided by geostrategic and prerogative considerations, chose significant urban centres such as Mediolanum, Augusta Treverorum, Ravenna, and Arelate as their residences. Protocol visits to Old Rome remained rare, evidencing the formalised subordination of the ancient city to New Rome, located at the strategically significant crossroads of the trade and geopolitical arteries of the Bosporus. From May 330, New Rome became the nucleus of the empire’s metanarrative identity, around which the cultural, administrative, and sacral aspects of imperial integration were structured.

The comprehension of the ontological significance of Constantinople as the sacred political and administrative centre of the Roman Empire necessitates the incorporation of a multidisciplinary approach to deconstruct its international legal subjectivity. The aspect of legal continuity, which enabled the transmutation of supreme authority to the Eastern part of the Empire following the recognition of a legal vacuum caused by the death of Julius Nepos in 480 AD, serves as a key analytical vector.^{38(p. 45)} A pivotal milestone in establishing Constantinople as a sacred space was the consecration ceremony in honour of the Blessed Virgin Mary, which took place on May 11, 330 AD. This act, functioning as a semiotic catalyst for transformational processes, simultaneously formalised the starting point of the Byzantine historical narrative, according to the perspectives of specialised historiographers.^{39(p. 320)}

The geopolitical relocation of the Empire’s administrative hub, initiated by Constantine the Great, represented a complex instrument of imperial expansion but in no way constituted a new state formation. Despite being nominally designated as the “Second Rome,” the Old Rome remained an organic component of a unified politico-legal organism. Conceptualisations speculating about the “decline” of the Roman Empire or its mythological transformation into “Byzantium” lack legal and political foundation, reducing them to philosophical-rhetorical constructs of predominantly abstract nature.

After 330 AD, the concept of “oecumenism” underwent a radical metamorphosis, acquiring theoretical and dogmatic normalisation within the framework of Christianitas – a highly organised metanarrative structure that internalised the sacred claims of Christian theology to universal dominance within the civilisational space of the oecumene.^{9(p. 12)} Constantine the Great’s administrative and reformative policies aimed at implementing theonomic principles into the political and legal architecture of the Empire epitomised the integrative synthesis of the sacred and the profane. Christian dogmatics functioned as the dominant interpretative paradigm, uniting metaphysical and eschatological categories of ecclesiological order with geopolitical and Christological concepts, collectively forming an integrative model of imperial legal subjectivity. The theoretical corpus of Christian thinkers, inspired by existential and ontological inquiries, constructed complex categories of subjectivity, including those correlating the anthropocentric dimension of free will with the normative-legal structures of the ecclesiastical hierarchy, state authority, and theonomic principles.

Exegetical studies of canonical and apocryphal texts acted as a catalyst for the incorporation of the idea of “divine election” into the legal framework of the political discourse of the empire, providing its sacred legitimation through mechanisms of transcendental sanctioning.^{38(p. 76)} As a result, the components of the concept of “divine election” were organically infiltrated into the normative structure of the imperial legal matrix. Emperors, manipulating these theocratic postulates, systematically employed them in the creation of federative agreements and diplomatic concordats, including peace treaties with Sasanian Iran, thereby demonstrating their not only ontological relevance but also geopolitical teleology.^{40(p. 122)}

The concept of the “Chosen People of God,” as a phenomenon of theocratic ideology, implicitly permeated the discursive field of the Roman normative-legal paradigm through mechanisms of theological transposition of Judeo-Christian doctrinal tenets. Imperial jurisprudence, represented by the public-law perspective on interpreting “divine election,” engaged in a rigid paradigmatic collision with Jewish orthodox cosmology, which articulated an essentialist notion of sacred monopoly rooted exclusively in a bloodline-defined substance.^{41(p. 34)} Within the framework of the imperial universalist concept, the archaic principle of ethnohistorical sacrality was radically transformed into a heterogeneous imperial narrative codifying Rome as an eclectic superstructure of ethnic, cultural, and social entities.

The “divine election” category was conceptually reformatted, acquiring an exoteric, transgressive character that incorporated any social agents assimilated into the Christian religious-cognitive continuum. The ecclesiological substrate of the Ecumenical Councils, complemented by regional synodal regulations, formed a complex system of vertically integrated hierarchy, cementing the connection of each individual with the imperial church-administrative framework. Since the ecclesiastical structure remained dependent on the state apparatus, the Christian community effectively functioned as a quasi-subject within the imperial politico-administrative architecture.^{42(p. 23)}

An analytical example of Christian infiltration into the international political sphere can be observed in the Roman-Sasanian diplomatic context. As early as 324 CE, Constantine the Great addressed the Shahanshah of Persia in an epistle containing an imperative demand for the immediate elimination of repressive measures against Christian ecclesial communities. In subsequent historical developments, successive emperors reiterated similar dispositions, most notably Theodosius the Lawgiver, whose activities demonstrated a phenomenological consistency in employing ideological rhetoric as a tool of geopolitical articulation.^10(p. 105) Although these acts were regarded by the Roman bureaucracy as pragmatic diplomatic instruments, from the standpoint of theocratic ideology, they served as manifestations of the sacred mission of the emperors as universal-historical protectors of the Christian oikoumene. Unifying the concepts of the “Christian world” and “oecumenism” was transformed into a syncretic ideological construct dominating the politico-ideological landscape of the late antiquity period.

Following Constantine the Great’s demise, with the exception of Julian the Apostate’s ideological deviation,^{15(p. 78)} no emperor attempted to desacralise Christian doctrine or sever it from the oecumenical paradigm. The conceptualisation of politico-religious integration, reinforced by the doctrine of imperial divine election, served as a robust ideological foundation for consolidating the empire as a universal, sacralised superstructure. The inculturation paradigm of Christianity, in contrast to the Jewish concept of eschatologically driven protectionism inherent in “divine election,” affirmed the idea of universal anthropological exclusivity, deeply correlating with the transcendental teleology of salvation. The initiatory act of sacramental Baptism understood as a hierophany, became a key mechanism for anthropological transformation, encompassing the sacred reinterpretation of human nature through an ontological metamorphosis. Salvation, therefore, was seen as a teleological possibility determined by a set of metaphysical prerequisites and existential responsibility, without which the eschatological prospect remained unattainable.^{7(p. 23)}

Incorporating foederati into the political-administrative structure of the Roman Empire during the Dominate period initiated processes of multi-vector jurisdictional stratification, leading to a configurational modification of imperial state-building and a transition to a hybrid governance model. Imperial legal practice distinguished multiple foederati categories based on treaty type, ranging from autonomous client kingdoms under foedus aequum to fully subordinated communities under deditio.^4,24 The interpenetration of ius Romanum and the hermeneutic barbarian legal codes resulted in legal dialecticism, within which imperial nomocracy gradually transformed under the influence of the political-legal relativisation of peripheral structures. The paradox of the situation lay in the fact that nominal imperial hegemony correlated with the gradual reduction of centralised jurisdiction and the adaptive legitimisation of barbarian institutional architectures, enabling a cumulative inversion of traditional power paradigms. As noted by Giuseppe Dari-Mattiacci and Dennis P. Kehoe, this process was reflected in the interaction between Roman legal norms and barbarian legal traditions, which led to a gradual transformation of the imperial legal system.^{28(p. 107)}

The military-strategic functionality of the foederati was articulated in their role as military-protectorate entities that carried out a dual mission: on the one hand, they ensured transitional defensive stability by intercepting exogenous threats; on the other hand, they gradually accumulated power potential, which contradicted imperial centralisation imperatives. The progressive barbarisation of the imperial army, which occurred through the evolutionary transformation of legionary doctrine, led to a structural redesign of the military hierarchy and the expansive political autonomization of foederati elites, causing the polycentric disintegration of state administration. As Dari-Mattiacci and Kehoe²⁸ emphasised, the Foederati’s growing role in military structures contributed to their autonomization and the gradual erosion of the empire’s centralised administrative authority. The systemic subversion of traditional imperial subordination, intensified by the foederati factor, led to the gradual endogenous erosion of Roman state-building and political-legal discourse, resulting in the irreversible fragmentation of the imperial power vertical, which inspired the genesis of post-imperial quasi-state formations (Table 2).

Table 2: Structural-functional model of foederati and their international legal personality in the dominate-era Roman Empire.
I. Institutional-Legal Paradigm and Normative-Juridical Stratification	Key Examples
Imperial Subordination and Quasi-Sovereign Institutions. The configurative integration of foederati into the systemic matrix of dominium Romanum occurred through mechanisms of latent vassalization, which entailed delegating administrative and military functions within controlled territories while simultaneously determining their subject status as subordinated yet autonomous political agents.	Visigoths 382–418: granted land in Thrace/Aquitaine, governed by own kings but obligated to provide troops11,12,19; Foederati retained customary law (ius gentium) for internal affairs but subject to ius Romanum for relations with empire.6,25
Hybrid Nature of Legal Interaction. The entities of foederatio functioned within a dual jurisdiction, where imperial law (ius Romanum) correlated with indigenous customary norms (ius gentium), leading to legal anomalies, particularly in the military and fiscal protection domains.	Dual jurisdiction example: Gothic communities under own chieftains for family/property law, but imperial courts for criminal cases involving Romans6,25; Fiscal arrangements: some foederati tax-exempt, others paid tribute in kind or military service.20,25
Extraordinary Status of the Foederati. Legal conventions and diplomatic agreements between the imperial administration and the foederati established a unique juridical regime under which barbarian communities acquired a limited legal personality and the obligation of auxilium et obsequium to the Roman emperor.	Treaty of 382 CE: Goths received land, autonomy, annual payments in exchange for military service11,12,19; Obligations of auxilium et obsequium: military aid and obedience to emperor25; Breach of treaty: Alaric’s revolts when payments ceased.23,27
II. Geopolitical Structuring and Strategic Functionality	Key Examples
Buffer Protectorates and Military Expansion. Localised federate formations served as a geopolitical bulwark on the imperial peripheries, minimising external political risks and neutralising threats from exogenous ethnopolitical conglomerates.	Gothic settlements along Danube frontier 380s–400s11,12,20; Frankish foederati in Rhine region under Julian and Valentinian14,20; Vandals in North Africa 435–439 transition from foederati to independent kingdom.20,25
Peripheral Militarisation and Transformation of the Roman Army. The decomposition of the traditional Roman military organisation occurred through the gradual replacement of legionary formations with foederati contingents, leading to the cumulative barbarisation of the imperial army and the modification of its operational-tactical doctrines.	Battle of Adrianople 378: Roman field army destroyed, replaced by Gothic foederati11,12; By 5th century, imperial armies predominantly barbarian under barbarian commanders (Stilicho, Ricimer, Odoacer)20,27; Traditional legionary system obsolete by 450 CE.20,25
Polycentric Defensive Doctrine and Imperial Control. The imperative of centralised military administration conflicted with the necessity of delegating defensive functions to foederati, creating an asymmetric dependence of the empire on the military contingents of barbarian rulers, whose loyalty remained contingent and situational.	Eastern empire maintained tighter control over foederati through payment systems and rotation16,20; Western empire increasingly dependent on autonomous barbarian forces due to fiscal collapse15,20,23; Asymmetric loyalty: foederati served when paid, rebelled when payments ceased.20,27
III. Political-Economic Mechanisms and Social Adaptation	Key Examples
Extractive Economic Model and Fiscal Capitulation. Federate formations were systematically incorporated into the empire’s economic system through obligatory contribution mechanisms, including providing human and material resources to the Roman administration. Aristocratic Integration and Political Syncretism. The barbarian elite gradually underwent a process of acculturation within the framework of imperial socio-political institutions, determining the evolution of ruling classes and fostering the development of a political dualism between the Roman bureaucracy and federate nobility.	Foederati received annona (grain distributions), land assignments (hospitalitas system), and tax exemptions20,25; Gothic settlement 382: land grants in Thrace with imperial food subsidies12,19; System created fiscal strain on empire while enriching foederati leaders. Barbarian elites entered Roman Senate and imperial service: Stilicho (Vandal), Ricimer (Suevic), Aspar (Alan)20,27; Intermarriage between Roman and barbarian aristocracies18,20; Dual identity: “Roman” in culture, “barbarian” in ethnicity.
Legitimization Mechanisms of Imperial Rule. The conceptualisation of Romanitas served as a normative instrument for justifying the policy of federalisation and ethnic assimilation of barbarian communities. However, the actual power distribution gradually evolved toward decentralisation and the localisation of imperial governance.	Imperial ideology of civilizing barbarians through Romanitas18,21; Christianity as integrative tool: Arian Goths vs. Nicene Romans created religious distinction30,32,33; Literary representations: foederati as “loyal barbarians” versus “enemies.”18
IV. Decomposition of Imperial Unity and the Inversion of Political Subjectivities	Key Examples
Systemic Erosion of Imperial Monolithism. The hypertrophy of foederati influence in the political spectrum led to the progressive fragmentation of imperial integrity and the formation of polycentric power structures operating on the autonomy and vassal dependence threshold.	Visigothic sack of Rome 410 CE23,27; Vandal kingdom in Africa 439–534 cut off grain supply to Rome20,25; Burgundian, Suevic, Frankish kingdoms established 410s–480s14,20,27; Final dissolution: Odoacer deposes Romulus Augustulus 476 CE.15,16
Permanent Usurpation Conflicts. The military and political activity of foederati increasingly became a catalyst for revolts, complicating centralised administrative mechanisms and accelerating disintegration processes.	Alaric’s revolts 395–41023,27; Gainas revolt in Constantinople 399–40020; Stilicho’s power struggle and execution 40827; Frequent clashes between foederati generals competing for control of imperial policy.
Paradigmatic Mutation of Imperial Authority. Due to prolonged symbiosis with foederati, the imperial political model’s evolution generated unique syncretic forms of governance, wherein the traditional imperial bureaucracy gradually ceded ground to barbarian military-administrative elites.	Barbarian kings ruling former Roman territories with Roman administrative structures: Theodoric in Italy, Clovis in Gaul, Theodoric II in Spain15,27; Continuity of Roman law and institutions under barbarian rule6,15,16; Byzantine claim to universal Roman authority over successor kingdoms.16,43
Source: Synthesized from Errington,16 Yilmazata,17 Hughes,19 Grant,20 Brandão,23 Melnyk,25 Elton,26 Heather and Rapley,5 Stickler,4 Heather,6 Ibbetson,24 and Dari-Mattiacci and Kehoe.28

Table 2 shows how foederati were used in four aspects: they had a mixed status between imperial subjects and independent allies (Section I), military-strategic status as buffers of the frontiers that both defended and destabilized the empire (Section II), economic and social one through land concessions and aristocratic intermarriages (Section III), and ultimate status of being transformed into independent political actors able to create their own barbarian kingdoms (Section IV).

The Gothic foedus of 382 is one example of this mixed legal status. After the disastrous Roman defeat at Adrianople in 378, in which Emperor Valens fell together with two-thirds of the eastern field army.^15–17 Theodosius I concluded a treaty with Visigoths which had never been used before. The agreement of 382, in contrast to the old-time deditio (unconditional surrender), gave Goths rights to settlement in Thrace and maintained native chieftains leading to tribal order.^16,17,25 The treaty created foedus iniquum whereby Goths were internally autonomous under ius gentium but was under imperial ius Romanum when external contacts and military service were concerned.^17,25

In return they were granted subsidies (annona) and pieces of land and supplied federate troops at their own leaders.^17,25 Such an arrangement demonstrates the main paradox of the quasi-federative model: Goths had a limited legal personality (ability to contract with the empire, bear separate juridical identity, and have delegated military power) but did not have full sovereignty. The foedus formed lopsided integration with barbarian autonomy alongside imperial suzerainty that shows how lex foedus worked as the juridical process that linked internal administrative hierarchy and external treaty connections of Rome in a stratified federative structure. Ammianus Marcellinus’s contemporary account of the post-Adrianople negotiations provides detailed evidence of how these treaty terms were formulated and implemented in practice.¹⁵

Repentance, conceptualised as metanoia, implicitly presupposed a cathartic ritual and the transcendental rethinking of the subject’s inner essence, achieved through a voluntary act free from coercive external determinants. Individual subjectivity in Christian discourse became a central axiom, enabling integration into the sacred community on the condition of voluntary and sincere acceptance of doctrinal truth and strict adherence to the normative regulations of ecclesiastical ethics. The imperial proclamation of the Edict of Thessalonica by Emperor Theodosius the Great (380 CE) marked a culminating point in the formation of a monopolistic sacred discourse that incorporated the concepts of Christian universalism and imperial absolutism into a unified integrative ideologeme. In this context, sacred monism and political domination functioned as an overarching civilisational narrative, unifying regional identities through theological and ideological homogenisation instruments. Polytheistic and syncretic religious traditions, marginalised by this universalist project, were gradually displaced by the concept of doctrinal orthodox monism, wherein the emperor and the church consolidated into a mutually dependent theocratic symbiosis.

Discussion

From the perspective of deep linguistic exegesis, both the social strata and privileged socio-cultural states of the Roman Empire were characterised by a high degree of polyglot competence. Greco-Latin bilingualism exemplified This linguistic dexterity in its normative form, which operated as a civilisational code with integrative potential. Notably, this linguistic duality was not confined to peripheral regions but was intrinsic even to the Italian heartland, the epicentre of imperial culture. Historical studies have paid much attention to the fall of the Western Roman Empire as a result of military downfall, economic breakdown, and foreign invasions.^43–47 Although these interpretations reveal much about the material conditions of late antiquity, they can be criticized because they do not take into account the legal-institutional processes that allowed the empire to survive all these difficulties so long. Such analyses are not mutually exclusive of the quasi-federative foederatio model which has been suggested in this paper, as lex foedus allowed Rome to respond to barbarian pressure, but at nominal unity and continuation of the law as based on the eastern imperial part.

The current discussion indicates that Christianitas ideology did not just serve as the spiritual teaching but provided juridical supports to asymmetric federalism. This theological justification of legal hierarchical pluralism is what separates the late Roman quasi-federative model of organization by the pre-constitutional republican formations as well as the contemporary federal systems of constitutional equality.^8–10,24 Integration of divine election speech in the treaty making cultures gave ideological sanctify to stratified sovereignty, where foederati communities had restricted legal personality though were still subordinate to imperial suzerainty.^4,24 This brings a very important question, which is, was such theologically based legal pluralism intrinsically sustainable, or did it harbor the structural germs of imperial disintegration that eventually came to fruition in the barbarian successor kingdoms?

Ethical discursive structures and customary legal regulations exhibited significant variability, shaped by tribal identity, regional differentiation, and local tradition, often resulting in remarkable fragmentation, even among neighbouring settlements. In legal terms, the incorporation of geographically and culturally remote territories, such as Iberia, Dacia, or the so-called barbarian ethnic groups like the Frisians and the Tauric-Crimean peoples, relied solely on the appropriation and acceptance of supreme imperial authority. This authority was embodied in the figure of the Roman emperor as the bearer of sacred sovereignty.

The foederatio concept used in the present paper disputes the excessively centralist views of late Roman rule by showing that legal pluralism was not a sign of decline, but an adjustment technique. Organized use of ius civile, ius gentium and ius foedus provided a dynamic judicial system that appeased different legal customs without sacrificing imperial hegemony.^24,28 This paradox can be illustrated using the Gothic foedus of 382, which was examined above: Goths gained the power of negotiating treaties and gaining internal autonomy but were still juridically subordinated to the Romans. This juridical structure helped the empire to control the integration of barbarians without necessarily losing its universalist pretensions.^48–50 At the same time, the question arises as to how such a heterogeneous, polyethnocultural, and polyconfessional polity managed to ensure its prolonged existence and periodic phases of civilisational zenith. Nevertheless, even religious unification through the Christian paradigm did not preclude the emergence of confrontational phenomena among representatives of divergent theological and cosmological worldviews. Furthermore, the empire frequently encountered structural crises, manifested in internal political disintegration and the intensification of external challenges.

The drawbacks of this research should be admitted. The introduction of modern terms like the federalism, legal personality and international law to late antique systems is full of methodological anachronism. Though heuristically useful, these terms project the analytical structures of the contemporary world onto a radically different political ontology.^4,20,24 Besides, the implicitness of the documentary record, especially concerning the particular juridical modes, through which foedera were negotiated and effected, limit the accuracy of legal-historical reconstruction. Modern documents such as Ammianus Marcellinus give a descriptive history but scarcely ever show the procedures involved in treaty making.¹⁵

The consequences of this study are not limited to the history of the late antiquity. This study has the potential to add to more general theorizing about the nature of the imperial government, legal pluralism, and the connection between universalist ideology and particularist practice by illustrating how the Roman Empire was a quasi-federative entity, incorporating different legal statuses into a sacral-political oikoumene. This model, in which the eastern empire retained the claims to universal Roman authority and only ruled a territory shrunk polity, hints at the fact that the conceptual impact of the foederatio did not stop in the year 476 CE.^20,21,38 These considerations highlight the necessity for a multifaceted and methodologically robust analysis of Roman civilisation as a multidimensional and complex historico-cultural phenomenon. Understanding its internal dynamics and external interactions demands an interdisciplinary approach, integrating perspectives from linguistics, legal history, theology, and socio-political studies to grasp the empire’s resilience and eventual transformations fully.

Conclusion

In the study of the federal state-territorial architecture of the Roman Empire and the ideological paradigms that dominated the cognitive elite of Roman society during the Dominate period, the international legal personality of this political entity was examined through the prism of its multifaceted theoretical and legal structure. This legal personality represents a polycentric composition of conceptual frameworks, legal archetypes, and normative institutions inextricably linked to the transformational processes of social morphology. As a holistic and polyvalent phenomenon, the legal personality of a state entity is shaped by social reflections on identity. It remains subject to constant adaptation to the dynamics of change in political and historical contexts.

The imperial experience of Rome during the Dominate era demonstrates a paradigmatic model of such legal personality, where the empire simultaneously positioned itself as a sovereign arbiter and an incorporative center in relations with barbarian confederations and other political entities within its peripheral sphere of influence. It has been established that the analytical conceptualization of the international legal personality of the Roman Empire during the Dominate period was rooted in a theologically legitimized discourse of sacred predestination, formulated through the concept of “divine election.” However, this concept materialized as an associative polystructure that integrated various ethnocultural and territorial substrates.

The article proves that the civilizational polyvalence of the Roman federation emphasized its hyper-inclusive capacity, which allowed it to incorporate polymorphic cultural archetypes into a single imperial domain. The proto-Christian phase was characterized by a differentiated dogmatic repertoire, which was determined by the geocultural parameters of the peripheral regions. The institutional practice of the Ecumenical Councils, aimed at achieving dogmatic unity, only partially mitigated doctrinal differences, leaving dominant regional and tribal variations in interpretation intact. These variations coexisted harmoniously within the broader framework of Roman federal universalism. Prospects for future research lie in an expanded analysis of the causes of excessive expansion, weakening of power, social tensions, economic problems, and external invasions that nullify the longevity of any empire, using the example of post-imperialist countries of the present day.

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Cite this article as:
Melnyk V. Revisiting  Roman Statehood: Examining the International Legal Framework of the Foederatio Model in the Context of the Later Roman Empire. Premier Journal of Science 2026;16:100234

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