1941August: Signing of the Atlantic Charter by the US President Franklin D. Roosevelt and British PM Winston S. Churchill
1942 January: 26 Allied nations fighting against the Axis Powers meet in Washington, D.C., to support the Atlantic Charter and sign the ‘Declaration by United Nations’
1943 December: Tehran Conference Declaration of the Three Powers (US, Britain and Soviet Union)
1945 February: Yalta Conference of the ‘Big Three’ (Roosevelt, Churchill and Stalin) decides to organise a United Nations conference on the proposed world organisation April-May: The 2-month long United Nations Conference on International Organisation at San Francisco
1945 June 26: Signing of the UN Charter by 50 nations (Poland signed on October 15; so the UN has 51 original founding members)
1945 October 24: the UN was founded (hence October 24 is celebrated as UN Day)
1945 October 30: India joins the UN