Zambia and south covering about three-quarters of the country; and the Congo basin in the north covering about one-quarter of the country. A very small area in the northeast forms part of the internal drainage basin of Lake Rukwa in Tanzania. In the Zambezi basin, there are a number of major rivers flowing wholly or partially through Zambia: the Kabompo, Lungwebungu, Kafue, Luangwa, and the Zambezi itself, which flows through the country in the west and then forms its southern border with Namibia, Botswana and Zimbabwe. Its source is in Zambia but it diverts into Angola, and a number of its
British South Africa Company Zimbabwe, and North-Eastern Rhodesia (now part of Zambia) and Portuguese Mozambique. It divided Manica, granting the western portion to the British South Africa Company. It also fixed the boundaries between the BSAC-administered territory of North-Western Rhodesia (now in Zambia), and Portuguese Angola. The northern border of the British territories was agreed as part of an Anglo-German Convention in 1890. The border between the British Central Africa Protectorate and the territory of the British South Africa Company in what is today Zambia was fixed in 1891 at the drainage divide between Lake Malawi and the Luangwa River. The terms of the