A German protectorate was formed in 1886 which was occupied at the beginning of the First World War by Japan. Japan was awarded a mandate by the League of Nations in 1919. During the Second World War the Islands were occupied by Allied forces in 1944, and became part of the UN Trust Territory of the Pacific Islands created on 18 July 1947 and administered by the USA. On 21 Oct. 1986 a Compact of Free Association with the USA came into force. The UN recognized the termination of the US Trusteeship on 22 Dec. 1990, and the Islands became a full UN member state on 17 Sept. 1991.