United Nations Trust Territories were the successors of the League of Nations mandates and came into being when the League of Nations ceased to exist in 1946. All of the trust territories were administered through the UN Trusteeship Council. The one territory not turned over was South West Africa, which South Africa insisted remain under the League of Nations Mandate. The main objection was that the trust territory guidelines required that the lands be prepared for independence and majority rule. Trust territories (and administering powers) were:

• Cameroons (Britain and France) - Divided between Nigeria and Cameroon in 1961.
• Nauru (Australia) - Granted independence in 1968.
• New Guinea (Australia) - The northern half of this trust territory had been a League of Nations mandate. The southern half had been Australian before World War I. After World War II, the two were combined into a unified trust territory which was granted independence as Papua New Guinea in 1975. The western half of the island, now part of Indonesia was never part of the trust territory.
• Trust Territory of the Pacific Islands (U.S.) - Split into The Republic of the Marshall Islands (1979), The Federated States of Micronesia (1979), The Commonwealth of the Northern Mariana Islands (1978), and The Republic of Palau (1981). With the exception of The Northern Mariana Islands, which is a commonwealth, they are all Associated States of the U.S.
• Ruanda-Urundi (Belgium) - Gained independence as the countries of Rwanda and Burundi.
• Somalia (Italy) - Granted independence in 1959.
• Tanganyika (Britain) - Became independent in 1961. Merged with Zanzibar in 1964 to form Tanzania.
• Togoland (Britain and France) - Merged with the Gold Coast in 1946, now know as Ghana.
• Western Samoa (New Zealand) - Granted independence in 1962, now known simply as Samoa.