The United Nations was founded as an international organization in 1945.
The UN officially came into existence on 24 October 1945, after the United Nations Charter had been ratified by its required major powers and a majority of its other signatories. The organization was created near the end of the Second World War to help maintain international peace, encourage cooperation, and support collective action on global problems.
Its predecessor, the League of Nations, had been established after the First World War but failed to prevent another major conflict. The UN therefore incorporated lessons from the League while giving its Security Council special responsibility for international peace and security.
The UN is headquartered in New York City, although much of its work takes place through offices and agencies around the world. United Nations Day is observed annually on 24 October, marking the Charter’s entry into force.