At the end of the war, 43 States were still Members of the League of Nations, though for all intents and purposes it had ceased to exist. However, the formal termination of the organization was necessary. A final and official disposition had to be taken concerning the transfer of the League of Nations’ properties to the United Nations: its concrete assets in the form of its buildings and grounds, its Library, and last but certainly not least, its archives and historical collections.
The Preparatory Commission set up at the San Francisco UNCIO conference, met in London with the Supervisory Commission of the League of Nations in order to do this. At the initiative of the British Foreign Office, the last Assembly of the League (the twenty-first) was held in Geneva on 8 Apr 1946. In his final speech, Lord Robert Cecil, one of the League of Nations’ founders, proclaimed that the efforts of those who had established the League of Nations were not lost, because without them the new international organization, the United Nations, could not exist. Lord Cecil closed the Assembly with the words: “The League is dead, long live the United Nations!”
The final act of transfer was signed in Geneva on 18 Apr 1946 by Sean Lester, the last Secretary-General of the League of Nations, and Wlodzimierz Moderow, the representative of the United Nations.
Thus, having handed over all of its assets to the United Nations, and having granted the new UN Secretariat full control of the League’s Library and archives, the 43 Members attending this last Assembly declared by unanimous vote that as of 20 Apr 1946, the League of Nations would cease to exist.