Zambezi Region with the United Kingdom. Leo von Caprivi arranged for the Caprivi strip to be annexed to German South West Africa in order to give Germany access to the Zambezi River as part of the Heligoland-Zanzibar Treaty. The German motivation behind the swap was to acquire a strip of land linking German South West Africa with the Zambezi River, providing easy access to Tanganyika (Tanzania) and an outlet to the Indian Ocean. Unfortunately for the Germans, the British colonisation of Rhodesia (Zimbabwe and Zambia) stopped them well upstream of Victoria Falls, which proved a considerable barrier to navigation on the Zambezi.
Luangwa River A tributary of the Shire River at the south end of the Great Rift Valley then cut back eastwards through the Chicao Trough and Zambezi Valley, capturing the southerly overspill of the Madumabisa Lake. This tributary became the Zambezi, which over millions of years captured the Kafue, Cuando and the upper Zambezi. Faulting lowered the land between the Luangwa Rift and the Zambezi Rift allowing Madumabisa Lake to drain out into the Zambezi in a channel which became the lower Luangwa River. The Luangwa Rift Valley and rivers within it form a natural barrier, with a very low population density.