In 1915, South Africa captured the German colony. It became a League of Nations Mandate territory, with the Union of South Africa administering it. In 1946, the League of Nations was replaced by the United Nations. The Mandate was supposed to become a Trust Territory when the League of Nations Mandates were transferred to the control of the UN. However, South Africa refused, regarding the territory as its fifth province (even though it was never formally incorporated into the Union of South Africa). In 1966, the United Nation terminated the Mandate and said that South Africa had no right to administer South-West Africa any more, but South Africa refused. In 1971, the South African occupation of the territory was illegal and that they should leave, but South Africa still refused.