About this time the Dutch came into conflict with the Kafirs. This vanguard of the great Bantu race had been invading southern Africa almost concurrently with the white people. Coming from the north-east and north they had—we may guess—crossed the Zambezi about the 6th century of the Christian Era; and their invasion had brought about the partial destruction and abandonment of the Sabaean and Arab settlements in the gold-mining districts of south-east Africa. The Semitic inhabitants of Zimbabwe and other mining centres had been driven back to the coast at Sofala. The progress of the black Bantu against the now more concentrated Hottentots and Bushmen was then somewhat slower, delayed no doubt by natural obstacles, by the desperate defence of the Hottentots, the tracts of waterless country on the west, and internecine warfare amongst themselves. Overlying the first three divisions of Bantu invaders there came down across the Zambezi from the districts of Tanganyika the great Zulu race, akin to the Bechuana-Basuto people who had preceded them, but less mixed with Hottentot blood, and speaking a peculiar Bantu language[92]. By the beginning of the 18th century this seventh wave—as one may call it—of Bantu invasion had swept as far south as the Great Kei River, and some years later had pushed the Hottentots back to the Great Fish River. In 1778 they came into direct contact with the Dutch; and the Governor of the Cape entered into an agreement with the Kafir chiefs that the Great Fish River should be the boundary between Dutch rule and Kafir settlement. Nevertheless, this agreement was soon transgressed by the Kafirs, who commenced raiding the Dutch settlers. In 1781 the first Kafir war ended disastrously for the Bantu invaders, who were driven back for a time to the Kei River. Eight years later they again invaded Cape Colony. A policy of conciliation was adopted, which ended by the Kafirs being allowed to settle on the Dutch side of the Great Fish River in 1789.