For 10 points, name this river along which Livingstone saw Victoria Falls.
An expedition traveling along this river was saved by the generosity of the teenage king Sekeletu. A pop song that became a war anthem claims that "We'll keep them north of" [this river] "til that river's running dry." This river's valley contained most of the estates called prazos established by Portuguese settlers who paid tribute to rulers of the Mutapa kingdom. The botanist John Kirk took part in an expedition impeded by rapids at (*) Cahora Bassa that aimed at discovering if this river provided a direct route to Africa's interior and was led by David Livingstone. The colonies of Northern and Southern Rhodesia were split along this river, so it now forms the northern border of Zimbabwe. For 10 points, name this river along which Livingstone saw Victoria Falls.
An expedition traveling along this river was saved by the generosity of the teenage king Sekeletu.
Zambezi River