giswayo. The Mthethwa kingdom then disintegrated and Shaka's Zulu
conquered and incorporated its chiefdoms. In 1818, the Zulu defeated the
Ndwandwe in a decisive battle at the Mhlatuse River and became the
dominant power throughout northern Nguni territory. By the mid-1820S,
Shaka's Zulu had established control over most territory from the Pongola
River in the north to beyond the Tugela River in the south and from the
mountain escarpment' to the sea.3 1
The transformation of the northern Nguni was accentuated by external
factors. Some historians believe that foreign trade was crucial in the rise of
the Zulu kingdom. Traders from the Portuguese settlement on Delagoa Bay
were.increasingly active in this period, bartering beads, brass, and other
imported commodities for ivory and cattle. Creating competition for con-
trol of the trade route, they probably intensified the conflicts and the
centralizing process.V The available evidence, including the recorded oral
traditions of the African informants, however, does not seem to warrant the
conclusion that the trade was sufficient to have been the primary cause of
the transformation.
One historian has gone so far as to assert that external forces-white
slave traders and white colonists and their Coloured allies-bore
most of