Founding the UN: Charter and Principal Organs

The United Nations was formally established at the San Francisco Conference, officially the United Nations Conference on International Organization, held between April 25 and June 26, 1945, with delegates from fifty countries. It built on wartime groundwork laid by the Atlantic Charter of 1941, the Declaration by United Nations signed on January 1, 1942, the Dumbarton Oaks proposals of 1944, and the Yalta agreements of February 1945, in which the great powers settled the outline of the veto. The UN Charter was signed on June 26, 1945, and entered into force on October 24, 1945, once it had been ratified by the five intended permanent members of the Security Council and a majority of the other signatories; Poland, absent from the conference, signed later and is counted as the fifty-first founding member. The new organization was conceived as a successor to the League of Nations, whose failure to prevent the Second World War shaped much of the Charter's design.