The United Nations Charter, the multilateral treaty which established the structure and functions of the UN, was signed on 26 June, 1945 in San Francisco, at the conclusion of the United Nations Conference on International Organization, and came into force on 24 October 1945.

A history of the United Nations in documents, including the first use of the name and the evolution of the international cooperation that established the need for a multi-national mechanism to prevent war.

AudioVisual Library of International Law on the U.N. Charter

  UN Charter Preamble poster from the UN Association-UK

  Preamble to the UN Charter, poster by the UN Association-UK