Covillan obeyed the orders, sending an exact account of his adventures to Lisbon, and proceeding with the other messenger to Ormus; where, having made sufficient inquiry, he sent his companion homewards, with the caravans that were going to Aleppo, and embarking once more on the Red sea, arrived in time at Abyssinia, and found the prince whom he had sought so long, and with such danger.

Two ships were sent out upon the same search, of which Bartholomew Diaz had the chief command; they were attended by a smaller vessel laden with provisions, that they might not return, upon pretence of want either felt or feared.

Navigation was now brought nearer to perfection.  The Portuguese claim the honour of many inventions by which the sailor is assisted, and which enable him to leave sight of land, and commit himself to the boundless ocean.  Diaz had orders to proceed beyond the river Zaire, where Diego Can had stopped, to build monuments of his discoveries, and to leave upon the coasts negro men and women well instructed, who might inquire after Prester John, and fill the natives with reverence for the Portuguese.

Diaz, with much opposition from his crew, whose mutinies he repressed, partly by softness, and partly by steadiness, sailed on till he reached the utmost point of Africa, which from the bad weather that he met there, he called cabo Tormentoso, or the cape of Storms.  He would have gone forward, but his crew forced him to return.  In his way back he met the victualler, from which he had been parted nine months before; of the nine men, which were in it at the separation, six had been killed by the negroes, and of the three remaining, one died for joy at the sight of his friends.  Diaz returned to Lisbon in December, 1487, and gave an account of his voyage to the king, who ordered the cape of Storms to be called thenceforward cabo de Buena Esperanza, or the cape of Good Hope.

Some time before the expedition of Diaz, the river Zaire and the kingdom of Congo had been discovered by Diego Can, who found a nation of negroes who spoke a language which those that were in his ships could not understand.  He landed, and the natives, whom he expected to fly, like the other inhabitants of the coast, met them with confidence, and treated them with kindness; but Diego, finding that they could not understand each other, seized some of their chiefs, and carried them to Portugal, leaving some of his own people in their room to learn the language of Congo.

The negroes were soon pacified, and the Portuguese left to their mercy were well treated; and, as they by degrees grew able to make themselves understood, recommended themselves, their nation, and their religion.  The king of Portugal sent Diego back in a very short time with the negroes whom he had forced away; and when they were set safe on shore, the king of Congo conceived so much esteem for Diego, that he sent one of those, who had returned, back again in the ship to Lisbon, with two young men despatched as ambassadors, to desire instructors to be sent for the conversion of his kingdom.