On June 26th 1945 the United Nations Charter was signed in San Francisco. The charter was the foundational treaty of the United Nations, it was signed at the San Francisco War Memorial and Performing Arts Center by 50 of the original 51 member countries. Poland was the 51st original member and they signed the charter two months later. It entered into force on 24 October 1945, after being ratified by the original five permanent members of the Security Council; the Republic of China (later replaced by the People’s Republic of China), France, the USSR (later replaced by the Russian Federation), the United Kingdom, and the United States, and a majority of the other signatories.