Answer:
What caused groups of Africans in Southern Africa to migrate north was that they were driven by their homelands by European imperialism. The effect of this situation was that these Africans moved north, creating other states.
Step-by-step explanation:
Since the imperialist colonization of European powers in Africa, many politically organized African nations lost much or all of their territorial possessions. The European powers, led by Britain, Portugal, Belgium, France and Germany, fully colonized the African territory, with the exception of Liberia and Ethiopia.
In the south of the African continent, colonization was carried out by Britain. After years of minor clashes, in 1879 the British carried out an open war against the Zulu Kingdom, which was the original sovereign of the South African lands. Sheltered in their technological and strategic superiority, the British triumphed and the Zulues, defeated, dispersed to the north, establishing small reigns in territories of today Mozambique and Botswana.