The Evolution of Private International Law: from Savigny’s Localization Theory to Contemporary European Integration

Abstract

The article examines the historical evolution and contemporary transformation of private international law (PIL), tracing its development from the nineteenth-century localization paradigm to the modern multilevel framework shaped by European integration, constitutionalization, and transnational regulatory interdependence. It argues that PIL should be understood not merely as a technical mechanism for determining applicable law, but as an autonomous and normatively significant discipline operating at the intersection of sovereignty, market integration, constitutional values, and transnational coordination.

The study reconstructs the foundations of the classical localization model, according to which private legal relationships possess objective connections to particular legal orders identifiable through connecting factors such as domicile, nationality, habitual residence, or place of performance. Within this framework, conflict-of-laws rules functioned as neutral coordinating norms intended to ensure predictability and international harmony of decisions.

The article further demonstrates how the twentieth century transformed this methodological neutrality. The expansion of welfare regulation, consumer and labor protection, and transnational commerce revealed that the choice of applicable law inevitably affects substantive outcomes and broader regulatory objectives. Consequently, PIL became increasingly materialized through mandatory rules, public policy exceptions, and protective connecting factors integrating considerations of social justice, constitutional rights, and regulatory policy into conflict-of-laws reasoning.

Special attention is devoted to the impact of European integration, which embedded PIL within a supranational and constitutionally layered legal order. The article concludes that contemporary PIL represents a synthesis rather than a rupture with classical theory, combining localization, party autonomy, constitutional sensitivity, and supranational coordination in order to balance legal certainty with normative responsiveness in an interconnected legal order.