The Bechuana, whom the Hottentots first met, were the most advanced of the Negro tribes of Central Africa. They had crossed the Zambesi in the fourteenth or fifteenth century; their government was a sort of feudal system with hereditary chiefs and vassals; they were careful agriculturists, laid out large towns with great regularity, and were the most skilled of smiths. They used stone in building, carved on wood, and many of them, too, were keen traders. These tribes, coming southward, occupied the east-central part of South Africa comprising modern Bechuanaland. Apparently they had started from the central lake country somewhere late in the fifteenth century, and by the middle of the eighteenth century one of their great chiefs, Tao, met the on-coming Hottentots. The Hottentots compelled Tao to retreat, but the mulatto Gricquas arrived from the south, and, allying themselves with the Bechuana, stopped the rout. The Gricquas sprang from and took their name from an old Hottentot tribe. They were led by Kok and Barends, and by adding other elements they became, partly through their own efforts and partly through the efforts of the missionaries, a community of fairly well civilized people. In Gricqualand West the mulatto Gricquas, under their chiefs Kok and Waterboer, lived until the discovery of diamonds. The Griquas and Bechuana tribes were thus gradually checking the Hottentots when, in the nineteenth century, there came two new developments: first, the English took possession of Cape Colony, and the Dutch began to move in larger numbers toward the interior; secondly, a newer and fiercer element of the Bantu tribes, the Zulu-Kaffirs, appeared. The Kaffirs, or as they called themselves, the Amazosas, claimed descent from Zuide, a great chief of the fifteenth century in the lake country. They are among the tallest people in the world, averaging five feet ten inches, and are slim, well-proportioned, and muscular. The more warlike tribes were usually clothed in leopard or ox skins. Cattle formed their chief wealth, stock breeding and hunting and fighting their main pursuits. Mentally they were men of tact and intelligence, with a national religion based upon ancestor worship, while their government was a patriarchal monarchy limited by an aristocracy and almost feudal in character. The common law which had grown up from the decisions of the chiefs made the head of the family responsible for the conduct of its branches, a village for all its residents, and the clan for all its villages. Finally there was a paramount chief, who was the civil and military father of his people. These people laid waste to the coast regions and in 1779 came in contact with the Dutch. A series of Dutch-Kaffir wars ensued between 1779 and 1795 in which the Dutch were hard pressed.