Since the 11th century, the region that is now Zimbabwe has been the site of several organised states and kingdoms such as the Rozvi and Mthwakazi kingdoms, as well as being a major route for migration and trade. The British South Africa Company of Cecil Rhodes first demarcated the present territory during 1890 when they conquered Mashonaland and later in 1893 Matabeleland after a fierce resistance by Matabele people known as the First Matabele War. Company rule ended in 1923 with the establishment of Southern Rhodesia as a self-governing British colony. In 1965, the conservative white minority government unilaterally declared independence as Rhodesia. The state endured international isolation and a 15-year guerrilla war with black nationalist forces; this culminated in a peace agreement that established universal enfranchisement and "de jure" sovereignty as Zimbabwe in April 1980. Zimbabwe then joined the Commonwealth of Nations, from which it was suspended in 2002 for breaches of international law by its then-government under Robert Mugabe, and from which it withdrew in December 2003. The sovereign state is a member of the United Nations, the Southern African Development Community (SADC), the African Union (AU), and the Common Market for Eastern and Southern Africa (COMESA). It was once known as the "Jewel of Africa" for its great prosperity.