Invasion may at least partially describe what the Xhosa experienced. While they, as well as the Khoe-San and Zulu, had long inhabited the region, when Europeans arrived they enforced their rules and norms. Yet, one of the chief political difficulties was that powerful Europeans, such as military men and governors, frequently did not stick around for very long. This, in combination with the dynamic political winds back in London, meant that colonial policies seemingly changed from year to year. Cattle raiding could be tolerated and then punished, with little forewarning. One of the interesting aspects is Mostert's implicit contention that by the time of the millenaria predictions in the 1850s, the Xhosa world had already been transformed beyond recognition.
This is a useful reference for understanding the forge of South African hitory and the ways in which the Cape encapsulated much of mid-nineteenth century globalization. It pulses with interesting characters and is a careful work of compelling scholarship.