Northern Force made up the northern prong of a pincer movement designed by Botha to encircle the German forces in South-West Africa. Two smaller South African columns came from the Cape and the Orange Free State (the latter coming over the deserts of Bechuanaland). The principal target was Windhoek, the capital of South-West Africa. The field of operations was arid and barren in the extreme; water was a precious commodity, so the South Africans and Southern Rhodesians brought thousands of tons of it with them. In the of desert between Walvis Bay and Windhoek, temperatures could rise to above in the daytime, then drop below freezing at night, all while desert winds blew sand and dust into every bodily and mechanical orifice. Germany based much of its defensive strategy in South-West Africa around the assumption that no enemy commander could feasibly attempt to advance across the desert from Walvis Bay to Windhoek, but Botha resolved to do exactly that.
