History

The United Nations was founded as a successor to the League of Nations, which was widely considered to have been ineffective in its role as an international governing body, in that it had been unable to prevent World War II. Some argue that the UN's major advantage over the League of Nations is its ability to maintain and deploy its member nations' armed forces as peace keepers. Others see such "peace keeping" as a euphemism for war and domination of weak and poor countries by the wealthy and powerful nations of the world.
The term "United Nations" (which appears in stanza 35 of Canto III of Byron's Childe Harold's Pilgrimage) was decided by Franklin D. Roosevelt and Winston Churchill during World War II, to refer to the Allies. Its first formal use was in the 1 January 1942 Declaration by the United Nations, which committed the Allies to the principles of the Atlantic Charter and pledged them not to seek a separate peace with the Axis powers. Thereafter, the Allies used the term "United Nations Fighting Forces" to refer to their alliance.
The idea for the UN was espoused in declarations signed at the wartime Allied conferences in Moscow, Cairo, and Tehran in 1943 . From August to October 1944, representatives of France, the Republic of China, the United Kingdom, the United States, and the Soviet Union met to elaborate the plans at the Dumbarton Oaks Estate in Washington, D.C. Those and later talks produced proposals outlining the purposes of the organization, its membership and organs, and arrangements to maintain international peace and security and international economic and social cooperation.
On 25 April 1945, the UN Conference on International Organizations began in San Francisco. In addition to the governments, a number of non-governmental organizations were invited to assist in drafting the charter. The 50 nations represented at the conference signed the Charter of the United Nations two months later on 26 June. Poland had not been represented at the conference, but a place had been reserved for it among the original signatories, and it added its name later. The UN came into existence on 24 October 1945, after the Charter had been ratified by the five permanent members of the UN Security Council—the Republic of China, France, the Soviet Union, the United Kingdom, and the United States—and by a majority of the other 46 signatories. That these countries are the permanent members of the Security Council, and have veto power on any Security Council resolution, reflects that they are the main victors of World War II or their successor states: the People's Republic of China replaced the Republic of China in 1971 and Russia replaced the Soviet Union in 1991 .
Initially, the body was known as the United Nations Organization, or UNO. However, by the 1950s, English speakers were referring to it as the United Nations, or the UN