The first Secretary-General of the United Nations was Trygve Lie, a Norwegian diplomat. He served from 1946 to 1952 and played a crucial role in establishing the UN as a significant force for international cooperation and peace following World War II. Lie was instrumental in shaping the organization’s structure and operations, navigating complex geopolitical landscapes during early Cold War tensions. His tenure involved addressing decolonization, the Korean War, and other global issues. Trygve Lie’s legacy is marked by his commitment to diplomacy and multilateralism, helping to lay the foundational principles that continue to guide the UN today.