During World War I, Germany's Pacific island territories were seized and became League of Nations mandates in 1923. Nauru became an Australian mandate, while Germany's other territories in Micronesia were given as a mandate to Japan and were named the South Seas Mandate. During World War II, Nauru and Ocean Island were occupied by Japanese troops, with also an occupation of some of the Gilbert Islands and were bypassed by the Allied advance across the Pacific. Following Japan's defeat in World War II its mandate became a United Nations Trusteeship administered by the United States as the Trust Territory of the Pacific Islands. Nauru became independent in 1968.