1. Introduction

The international political system as it exists today is the product of a complex historical evolution shaped by wars, treaties, ideological shifts, and socio-economic transformations. Among the pivotal moments in this evolution, the Treaty of Westphalia of 1648 stands out as a foundational event that formalized the principles of state sovereignty and non-interference, which remain central to international relations. This module examines the historical background and significance of the Westphalian settlement, exploring how it established the conceptual basis for modern sovereignty. It then traces the subsequent evolution of the modern state system, analyzing key developments from the seventeenth century to the present.