The treaty that ended the Thirty Years’ War in 1648, significantly altering the political map of Europe, is the Peace of Westphalia. This series of treaties concluded the protracted conflict marked by religious and territorial disputes among European powers, particularly between Catholics and Protestants. The Peace of Westphalia not only recognized the sovereignty of individual states but also established principles of diplomatic negotiation and coexistence. Its legacy is significant, as it laid the groundwork for the modern nation-state system and the concept of national sovereignty, influencing international relations and political frameworks for centuries.