Zambia tributaries rise in Angola's central highlands. The edge of the Cuando River floodplain (not its main channel) forms Zambia's southwestern border, and via the Chobe River that river contributes very little water to the Zambezi because most is lost by evaporation. Two of the Zambezi's longest and largest tributaries, the Kafue and the Luangwa, flow mainly in Zambia. Their confluences with the Zambezi are on the border with Zimbabwe at Chirundu and Luangwa town respectively. Before its confluence, the Luangwa River forms part of Zambia's border with Mozambique. From Luangwa town, the Zambezi leaves Zambia and flows into Mozambique, and
Botswana–South Africa border the Limpopo River, and the border runs along the Limpopo to its confluence with the Shashe River, which is the tripoint with Zimbabwe. The western portion of the border from the Namibian tripoint to Ramatlabama was the border between British Bechuanaland to the south and the Bechuanaland Protectorate to the north. British Bechuanaland was constituted as a Crown Colony by proclamation in 1885, and incorporated the lands of the Tswana people situated to the south of the Molopo River, west of the South African Republic (the Transvaal) and not already part of the Cape Colony. The Tswana lands north of