In August, 1486, Bartholomew Diaz, the most eminent of a line of Portuguese navigators, had departed on the African route, with two consorts. As he neared the latitude of the looked-for Cape, he was driven south, and forced away from the land, by a storm. When he was enabled to return on his track he struck the coast, really to the eastward of the true cape, though he did not at the time know it. This was in May, 1487. His crew being unwilling to proceed farther, he finally turned westerly, and in due time discovered what he had done. The first passage of the Cape was thus made while sailing west, just as, possibly, the mariners of the Indian seas may have done. In December he was back in Lisbon with the exhilarating news, and it was probably conveyed to Columbus, who was then in Spain, by his brother Bartholomew, the companion of Diaz in this eventful voyage, as Las Casas discovered by an entry made by Bartholomew himself in a copy of D'Ailly's Imago Mundi. Thirty years before, as we have seen, Fra Mauro had prefigured the Cape in his map, but it was now to be put on the charts as a geographical discovery; and by 1490, or thereabouts, succeeding Portuguese navigators had pushed up the west coast of Africa to a point shown in a map preserved in the British Museum, but not far enough to connect with what was supposed with some certainty to be the limit reached during the voyages of the Arabian navigators, while sailing south from the Red Sea. There was apparently not a clear conception in the minds of the Portuguese, at this time, just how far from the Cape the entrance of the Arabian waters really was. It is possible that intelligence may have thus early come from the Indian Ocean, by way of the Mediterranean, that the Oriental sailors knew of the great African cape by approaching it from the east.
Portuguese missionaries to Egypt.
Such knowledge, if held to be visionary, was, however, established with some certainty in men's minds before Da Gama actually effected the passage of the Cape. This confirmation had doubtless come through some missionaries of the Portuguese king, who in 1490 sent such a positive message from Cairo.
But while the new exertions along the African coast, thus inadvertently instigated by Columbus, were making, what was becoming of his own westward scheme?
The Portuguese send out an expedition to forestall Columbus.
The story goes that it was by the advice of Cazadilla that the Portuguese king lent himself to an unworthy device. This was a project to test the views of Columbus, and profit by them without paying him his price. An outline of his intended voyage had been secured from him in the investigation already mentioned. A caravel, under pretense of a voyage to the Cape de Verde Islands, was now dispatched to search for the Cipango of Marco Polo, in the position which Columbus had given it in his chart. The mercenary craft started out, and buffeted with head seas and angry winds long enough to emasculate what little courage the crew possessed. Without the prop of conviction they deserted their purpose and returned. Once in port, they began to berate the Genoese for his foolhardy scheme. In this way they sought to vindicate their own timidity. This disclosed to Columbus the trick which had been played upon him. Such is the story as the Historie tells it, and which has been adopted by Herrera and others.
Columbus leaves Portugal, 1484.
At this point there is too much uncertainty respecting the movements of Columbus for even his credulous biographers to fill out the tale. It seems to be agreed that in the latter part of 1484 he left Portugal with a secrecy which was supposed to be necessary to escape the vigilance of the government spies. There is beside some reason for believing that it was also well for him to shun arrest for debts, which had been incurred in the distractions of his affairs.