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.
Zambezi tributary of the Shire River in the East African Rift's southern extension through Malawi eroded a deep valley on its western escarpment. At the rate of a few cm per year, this river, the Middle Zambezi, started cutting back the bed of its river towards the west, aided by grabens (rift valleys) forming along its course in an east-west axis. As it did so it captured a number of south-flowing rivers such as the Luangwa and Kafue. Eventually the large lake trapped at Makgadikgadi (or a tributary of it) was captured by the Middle Zambezi cutting back towards it, and