 In addition to various Cabinet appointments, he served as Prime Minister of the Union of South Africa from 1919 to 1924 and from 1939 to 1948.He played a leading part in the post war settlements at the end of both world wars, making significant contributions towards the creation of both the League of Nations and the United Nations.This article is about Jan Smuts in the government of South Africa when part of the British Empire, from the Transvaal's defeat at the end of the Second Boer War in 1902 until the creation of the Union of South Africa in 1910.