The Charter of the United Nations laid the groundwork for the modern-day UN. Adopted on June 26, 1945, in San Francisco, the Charter established the principles and organization of the UN aimed at fostering international cooperation, peace, and security. It outlined the rights and responsibilities of member states, emphasizing the importance of diplomatic dialogue, human rights, and social progress. The Charter sought to prevent conflicts like those seen in World War I and World War II by promoting disarmament, collective security, and cooperation among nations. Its establishment marked a significant step toward multilateralism in international governance.