October 24, 194580 years ago
United Nations officially comes into existence

Key facts
- Location
International; UN Charter signed in San Francisco
- Outcome
UN Charter entered into force
United Nations established
The United Nations Charter entered into force on 24 October 1945 after the required ratifications, formally establishing the new organization. Created after two world wars, the UN was intended to support international peace, cooperation and peaceful settlement of disputes.
Why a new organization was needed
The destruction of the Second World War made international cooperation an urgent priority. The League of Nations, founded after the First World War, had not prevented another global conflict. Wartime allies discussed a stronger system in which governments could meet, negotiate and respond to threats to peace. The eventual United Nations was not meant to erase disagreements among states; it was designed to give them institutions and procedures through which to address problems before they developed into wider wars.
The Charter and ratification
Delegates gathered in San Francisco from April to June 1945 to draft a charter defining the new organization. The Charter was signed on 26 June, but signing was not the same as legal entry into force. Under its own rules, ratifications were required from the five powers designated as permanent Security Council members and a majority of other signatories. Those conditions were satisfied on 24 October 1945. This is why the UN’s official birthday falls in October rather than June.
What the UN was designed to do
The Charter created a General Assembly where member states could debate, a Security Council with particular responsibilities for international peace and security, and other bodies for economic, social and legal questions. It also recognized principles including sovereign equality and the obligation to settle disputes peacefully. Not every question was settled in 1945, and the special powers of the permanent Security Council members would provoke lasting debate. The institution was nevertheless built to outlast particular governments and crises.
The meaning of UN Day
October 24 became United Nations Day, a yearly reminder of the Charter’s entry into force. The organization went on to work in peacekeeping, humanitarian assistance, human rights and international development, while facing criticism over political divisions and limits to enforcement. Its history contains both achievements and failures. The precise event remembered on this date is legal and institutional: a charter became binding and a permanent forum for global diplomacy officially came into existence.
Related events
Also on this day
Sources
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