Lesotho is a landlocked mountainous kingdom bordered entirely by the Republic of South Africa. The enclave lies at the head of the Orange River, with over 80% of its land residing 1,800 metres above sea level. The earliest human evidence in the region dates back 40,000 years, with the ancestors of the Khoisan hunter-gatherers. Successive Bantu migrations between the third and eleventh centuries led to an established Sotho–Tswana presence in the Lesotho hinterland, where the people referred to themselves as Basotho. During the nineteenth century, political and demographic upheavals occurred with the arrival of displaced Zulu clans, and the appearance of Voortrekkers from the Cape Colony in search of arable land. In 1818, Moshoeshoe I became the first king of the Basotho people and by 1868 requested protection by the British in 1868, but further violent disputes over land resulted in Basutoland being annexed to the Cape Colony. The British organized Basutoland into a territory with direct control from their High Commissioner for South Africa in 1884. In 1910, Basutoland declined union with South Africa and in 1966 it became an independent and sovereign member of the Commonwealth of Nations as the Kingdom of Lesotho. The capital and largest city is Maseru. Estimated population of Lesotho in 2009 was 2,067,000.