 Legislative power was vested in a Parliament consisting of the Monarch, a Senate, and a House of Assembly.For most of the Union's existence, the South Africa Act provided for each Province to have equal representation in the upper house, the Senate, and Senators were chosen by an electoral college made up of the Province's members in the House of Assembly and the members of the provincial legislature.The composition and election of the Senate would later be modified as part of the move towards apartheid and the establishment of the Republic of South Africa.