First session of the United Nations General Assembly
The first session of the United Nations General Assembly was the inaugural meeting of the UN's principal deliberative, policy-making and representative organ. It opened on 10 January 1946 at the Methodist Central Hall in London, and brought together representatives of the original 51 member states under the recently ratified United Nations Charter.
Source: Wikipedia — First session of the United Nations General Assembly (CC BY-SA 4.0)