In origin, the Portuguese search for India was but the sequel to the century-old conflict with the Moslem, a more subtly conceived crusade. Losing their hold on the Spanish Peninsula, the Moors were still intrenched in Africa; and in 1415 a Portuguese fleet, crossing to the northern point opposite Gibraltar, took and plundered the fortress and city of Ceuta. It was on this occasion, and subsequently in 1418, that Prince Henry gained from Moorish prisoners reliable information of the rich caravan trade from the Senegal and Gambia Rivers, and from the Gold and Ivory Coasts on the Gulf of Guinea, to Timbuctoo, and across the desert to Ceuta and Tunis: information which strengthened, if it did not inspire, the guiding motive of his life. For enriching Portugal and undermining the Moorish power in Africa, how much more effective than the plunder of Ceuta would be the conquest of the Guinea Coast! Once round the shoulder of Africa and the thing was done! And who could say what lay beyond the Gulf of Guinea? Prester John, perhaps, or the shining treasures of India.

And so, returning from Africa in 1418, the Prince retired to the famous Sacred Promontory in the Province of Algarve, where he gave the best energies of forty years to the task of African exploration. Backed by the resources of the state, commanding the best scientific knowledge of the day, patiently enduring "what every barking tongue could allege against a Service so unservicable and needlesse," he sent out year after year the most skillful and daring sailors of Italy and Portugal, and inspired them anew, as often as they returned baffled and discouraged, with his own perennial enthusiasm. Between 1435 and 1460, famous captains in his service—Gil Eannes, Denis Diaz, the Venetian Cadamosto—made those crucial voyages round the Point of Bojador, past the desert to Cape Verde, and beyond as far as Sierra Leone. After 1443 the labors of the Navigator were no longer thought to be wasted; for when the rich traffic in slaves and gold was opened up to Portugal, the greed of gain was added to scientific interest as a motive for exploration:—"Gold," says the chronicler, "made a recantation of former Murmurings, and now Prince Henry was extolled."

When Prince Henry died in 1460 no ship had sailed beyond Sierra Leone; but the nation had caught the spirit of the master, and in the next generation the search for India replaced the exploration of the Gulf of Guinea. Escobar crossed the Equator in 1471, and fourteen years later Diego Cam sailed a thousand miles beyond the mouth of the Congo River. It was in 1486 that Bartholomew Diaz, third of that family to forward African exploration, left Lisbon determined to reach the Indian Ocean. Having passed the farthest point reached by Diego Cam the year before, he put out to sea and ran before the strong northern gale for fourteen days. Turning eastward in search of the coast, and then north, land was at last sighted to the west. The northerly trend of the coast, as they pushed on four hundred miles farther, assured Diaz that he was, indeed, in the Indian Ocean. The valiant captain would have gone on to India, but the crew forced him to turn back. It was on the return voyage that he first saw the southernmost point of Africa—object of so many notable ventures: the Tempestuous Cape, as Diaz would have named it; but no, replied the king, may it rather prove the Cape of Good Hope.

Among those for whom the voyage of Diaz was of vital importance was an unknown Italian map-maker, already possessed with the one idea that was to make him more famous than Diaz, but which as yet had brought him only poverty and humiliation. Christopher Columbus, son of a Genoese wool-comber, sailor and trader and student of men and of maps from the age of fourteen, had come, about the year 1477, from London to Lisbon, where he married in 1478 Felipe Moñiz de Perestrello, whose father had been a captain in the service of Prince Henry and first governor of Porto Santo. Student of cartography and professional map-maker, expert sailor himself, who had probably been to the Gold Coast, associating with captains and sailors in this seaport town of Lisbon, Columbus must have picked up all the common sailors' gossip of the age, and all the best-known scientific speculation. With the Greek tradition that the Indies might be reached by sailing west from the Pillars of Hercules, he was probably familiar, even if he had not read the famous statement of Aristotle in Roger Bacon's Opus Majus, or in the Imago Mundi of Pierre d'Ailly; familiar also he certainly was with the persistent mediæval legends of islands in the western Atlantic,—Atlantis, and the Seven Cities, and Isles of St. Brandan.

Here in Lisbon, poring over old maps, by fortunate miscalculation underestimating the size of the earth, noting, as expedition after expedition returned, the indefinite southern extension of the African coast, Columbus became convinced that the Portuguese had chosen the longer route to the East, and that "the Indies in the east might in the Earth's Globositie be as readily found out by the west, following the sun in his daily journey." To reach the Indies by sailing west, and to discover, for the king who should authorize him, such new lands as might fall his way, became henceforth the consuming ambition of his life. It was a project which he had already, about 1484, laid before the King of Portugal. Repulsed, and at the same time betrayed, he went to Spain, where he was encouraged by the Count Medina Celi and the Cardinal Mendoza, only to have his plan rejected by the Council to which it was referred. The queen was not unfavorably disposed, but the Moorish wars occupied her days and depleted her treasury. Weary with following the court about, it must have been with profound discouragement that Columbus heard of the success of Diaz in 1488. For the time was short; Diaz had all but reached the goal, and one more voyage might bring the Portuguese to India before Columbus could induce the Spanish sovereigns to try the better plan.

But the Portuguese did not follow up their advantage, and after four more years of waiting, when the Moorish wars were successfully concluded by the conquest of Granada, Columbus at last obtained a favorable hearing from Ferdinand and Isabella. By the King and Queen of Spain Christopher Columbus was authorized to "discover and acquire certain islands and mainland in the ocean"; to appropriate for himself a tithe of the precious metals which might be found there, and to be "Admiral of the said islands and mainland, and Admiral and Viceroy and Governor therein." Within three months all was ready, and on Friday, August 3, 1492, the famous expedition, about ninety men in three small ships, with compass and astrolabe for determining direction and latitude, but no log for the dead reckoning, left Palos for the Canaries. It was not with adverse winds or a rough sea that the admiral had to contend, but with a superstitious crew often moved to mutiny,—terrified by the strange variation of the needle, questioning whether the steady trade winds that bore them on would ever permit them to return, certain that the Sargasso Sea would prove that impenetrable marsh of which they had heard. With unfailing resourcefulness, with patience and tact, with the compelling force of a masterful character, the great commander vanquished fear and superstition, never doubting that since "he had come to go to the Indies he would keep on till he found them by the help of God."

It was on the 11th day of October, seventy days out from Spain, and none too soon, that land was sighted; and on the following morning Columbus, bearing the cross of the Church on the banner of Castile, set foot on one of the minor Bahamas, the present Watling's Island. For two months and a half he cruised in these waters, seeking gold and spices, and the evidence of great cities, "still resolved to go to the mainland and the City of Quinsay, and to deliver the letters of your Highness to the Grand Can, requesting a reply and returning with it." He did not find Quinsay or the Grand Khan, but he discovered Santa Maria, and Hayti, where the first Spanish colony in the New World was established, and Cuba, which was taken to be the mainland. Resting in this belief, the admiral set out for home, reaching Palos February 15, 1493. And it was straightway reported in Europe that the Genoese captain had "found that way never before known to the east."

The East, yet not the desired part of it,—not Cipango, or the city of Quinsay, nor yet the rich Moluccas. These, however, Columbus never doubted, would be easily found. Others were less sanguine. The Spanish sovereigns seemed scarcely convinced that the islands of Columbus were parts of Marco Polo's Indies; while King John suspected that they were really within the southern Guinea waters belonging to Portugal. Therefore the Portuguese King hastened to secure, by papal bulls and the Treaty of Tordesillas with Spain in 1494, the famous Demarcation Line which reserved to Portugal, for exploration and discovery, the regions lying east, and to Spain the regions lying west, of a meridian three hundred and seventy leagues west of the Cape Verde Islands. And five years later, when Vasco da Gama at last reached Calicut by the eastern route, no one could longer maintain, so it seemed to the Portuguese King, that the Spanish explorers were in Indian waters. In July, 1499, the news of Da Gama's success reached Lisbon; and Emanuel, with pleasant malice, hastened to inform the Spanish sovereigns that the real Indies had been visited "by a nobleman of our household," and that he had found there, what every one expected to find, what Columbus had nevertheless not found, "large cities, and great populations"; as evidence of which he had brought home "cinnamon, cloves, ginger, nutmeg, pepper, also many fine stones of all sorts; so that henceforth all Christendom in this part of Europe shall be able, in large measure, to provide itself with these spices and precious stones."

The conclusion which the Portuguese King so eagerly accepted was meanwhile confirmed by every western voyage. Beyond the islands which Columbus had discovered, an interminable barrier everywhere blocked the way. In 1498, the admiral himself had touched the mainland near Trinidad, and in 1502 he explored the Bay of Honduras. Hojeda and Pinzon, in 1499 and 1500, sailed along nearly the whole northern coast of South America, while in 1501 Americus Vespucci followed the eastern coast from the point of Brazil as far as 35° south latitude. It could no longer be doubted, by those at least who had seen the great mouths of the Amazon and the Plate Rivers, that behind this long stretch of coast lay an immense continent; a projection of Asia, doubtless, separated from it by some narrow strait, perhaps, or possibly by an unknown sea: at any rate, a "boundless land to the south," as Columbus reported; and which "may be called a new world, since our ancestors had no knowledge of it," as Vespucci thought; "a fourth part of the world," said Waldseemüller in his Introduction to Cosmography, published in 1507, "which since Americus discovered it may be called Amerige—i.e., Americ's land or America." In 1506 Bartholomew Columbus prepared the earliest extant map showing this Mondo Novo, represented as a projection of southern Asia and extending three fourths of the distance to the shoulder of Africa.

This new world of America, a seemingly impenetrable barrier, lay between Spain and the Indies—the real Indies from which the Portuguese were yearly bringing home a rich freightage of gems and spices. In 1509 their ships first reached Malacca; two years later that "golden Chersonese" was taken by Albuquerque; and in 1512 D'Abreu returned with the first cargo of cloves from Amboina and Banda, the very "isles where the spices grow." To find a passage through the Mondo Novo, which Columbus had discovered, became therefore the aim of future Spanish exploration—inspiring the second voyage of Pinzon in 1508, the expedition of Balboa across the Isthmus in 1513, the fatal last cruise of Solis to the mouth of the Plate River, and the final triumphant venture of Ferdinand Magellan.