In 1448, under Prince Henry’s directions, a fort had been built on the Bay of Arguin, to the south of Cape Blanco; and a few years later a Portuguese company was formed for carrying on a trade with the Guinea coast in slaves and gold. The first expedition sent out by this company resulted in the despatch of 200 Negro slaves to Portugal, and thenceforward the slave trade grew and prospered. It at first resulted in but little misery for the slaves, who exchanged a hunted, hand-to-mouth existence among savage tribes in Africa for relatively kind treatment and comfortable living in beautiful Portugal, where they were much in favour as house servants. In 1481 the Portuguese, who had been for some years examining the Gold Coast, decided to build a fort to protect their trade there. In 1482 the fort was completed and the Portuguese flag raised in token of sovereignty. This strong place, for more than a hundred years in possession of the Portuguese, was called Saõ Jorge da Mina[53]. In the same year in which this first Portuguese post was established on the Gold Coast[54], exploration of the African coast was carried on beyond the mouth of the Ogowe by Diogo Cam, who discovered the mouth of the Congo in 1482, and sailed up that river about as far as Boma. In 1485 Diogo Cam returned with a stronger expedition which sailed and rowed up the Congo to the mouth of the Mpozo river, just below the Yellala Falls[55]. Diogo Cam’s discoveries were continued by Bartolomeu Diaz de Novaes, who, passing along the south-west coast of Africa, rounded the Cape of Good Hope in stormy weather without knowing it, and touched land on February 3, 1488, at Mossel Bay, then again at Algoa Bay, Cape Padrone and the mouth of the Great Fish river. Here the timorous officers and crew insisted on a return westwards. On the homeward voyage Diaz beheld and named Cape Agulhas, and also “Cabo Tormentoso,” the terminal point of South Africa, which was afterwards christened by Diaz, or by his monarch, King Joaõ II, “the Cape of Good Hope.”