The Peace of Westphalia, concluded in 1648, marked a significant turning point in European political history, emphasizing state sovereignty and the principle of non-interference in domestic affairs. This peace ended the Thirty Years' War and recognized the coexistence of multiple sovereign states, fostering a new international order. By acknowledging the rights of princes and the political legitimacy of states, the treaties established a framework for diplomacy and interstate relations based on mutual recognition. The concept of sovereignty introduced by the Peace of Westphalia laid the groundwork for modern international law and the formation of the state system that governs diplomatic practices today.