As the trade of the country did not cover the outlay, Henry began in 1442 to capture negroes, who were imported as slaves, or sold with advantage to local chiefs. In five years, 927 blacks from Senegambia reached the Lisbon market; and, later on, the Guinea coast supplied about a thousand every year. That domestic institution was fast disappearing from Europe when it was thus revived; and there was some feeling against the Infante, and some temporary sympathy for his victims. On the other side, there were eminent divines who thought that the people of hot countries may properly be enslaved. Henry the Navigator applied to Rome, and Nicholas V issued Bulls authorising him and his Portuguese to make war on Moors and pagans, seize their possessions, and reduce them to perpetual slavery, and prohibiting all Christian nations, under eternal penalties, from trespassing on the privilege. He applauded the trade in negroes, and hoped that it would end in their conversion. Negro slavery struck no deep root in Europe. But the delusion, says Las Casas, lasted to his own time, when, half a century after the death of its founder, it began to control the destinies of America.

Henry's brother, the Regent Dom Pedro, had visited the courts of Europe, and brought Marco Polo's glowing narrative of his travels in the Far East, still, in Yule's edition, one of the most fascinating books that can be found. Emmanuel the Great, in the Charter rewarding Vasco da Gama, affirms that, from 1433, the Infante pursued his operations with a view to India. After his death, in 1460, they were carried on by the State, and became a secondary purpose, dependent on public affairs. Africa was farmed out for some years, on condition that a hundred leagues of coast were traced annually. There was a moment of depression, when the Guinea coast, having run eastward for a thousand miles and more, turned south, apparently without end. Toscanelli of Florence was a recognised authority on the geography of those days, and he was asked what he thought of the situation. No oracle ever said anything so wise as the answer of the Tuscan sage. For he told them that India was to be found not in the East, but in the West; and we shall see what came of it twenty years later, when his letter fell into predestined hands. The Portuguese were not diverted from their aim. They knew quite well that Africa does not stretch away for ever, and that it needed only a few intrepid men to see the end of it, and to reach an open route to Eastern Asia. They went on, marking their advance beyond the Congo, and erected crosses along the coast to signify their claim; but making no settlements, for Africa was only an obstruction on the way to the Indies.

Each successive voyage was made under a different commander, until 1486, when the squadron of Bartholomew Diaz was blown offshore, out into the Atlantic. When the storm fell he sailed east until he had passed the expected meridian of Africa, and then, turning northward, struck land far beyond Cape Agulhas. He had solved the problem, and India was within his reach. His men soon after refused to go farther, and he was forced to renounce the prize. On his way back he doubled the Cape, which, from his former experience, he called the Cape Tempestuous, until the king, showing that he understood, gave it a name of better omen. Nevertheless, Portugal did no more for ten years, the years that were made memorable by Spain. Then, under a new king, Emmanuel the Fortunate, Vasco da Gama went out to complete the unfinished work of Diaz, lest Columbus, fulfilling the prophecy of Toscanelli, should reach Cathay by a shorter route, and rob them of their reward. The right man had been found. It was all plain sailing; and he plucked the ripe fruit. Vasco da Gama's voyage to the Cape was the longest ever made till then. At Malindi, on the equatorial east coast of Africa, he found a pilot, and, striking across the Indian Ocean by the feeble monsoon of 1497, sighted the Ghats in May. The first cargo from India covered the expenses many times over. The splendour of the achievement was recognised at once, and men were persuaded that Emmanuel would soon be the wealthiest of European monarchs. So vast a promise of revenue required to be made secure by arms, and a force was sent out under Cabral.

The work thus attempted in the East seemed to many too much for so small a kingdom. They objected that the country would break its back in straining so far; that the soil ought first to be cultivated at home; that it would be better to import labour from Germany than to export it to India. Cabral had not been many weeks at sea when these murmurs received a memorable confirmation. Following the advice of Da Gama to avoid the calms of the Gulf of Guinea, he took a westerly course, made the coast of South America, and added, incidentally and without knowing it, a region not much smaller than Europe to the dominions of his sovereign.

The Portuguese came to India as traders, not as conquerors, and desired, not territory, but portable and exchangeable commodities. But the situation they found out there compelled them to wage war in unknown seas, divided from supports, and magazines, and docks by nearly half the globe. They made no attempt on the interior, for the Malabar coast was shut off by a range of lofty mountains. Their main object was the trade of the Far East, which was concentrated at Calicut, and was then carried by the Persian Gulf to Scanderoon and Constantinople, or by Jeddah to Suez and Alexandria. There the Venetians shipped the products of Asia to the markets of Europe. But on the other side of the isthmus the carrying trade, all the way to the Pacific, was in the hands of Moors from Arabia and Egypt. The Chinese had disappeared before them from Indian waters, and the Hindoos were no mariners. They possessed the monopoly of that which the Portuguese had come to take, and they were enemies of the Christian name. The Portuguese required not their share in the trade, but the monopoly itself. A deadly conflict could not be avoided. By the natives, they were received at first as friends; and Vasco da Gama, who took the figures of the Hindoo Pantheon for saints of the Catholic Calendar, reported that the people of India were Christians. When this illusion was dispelled, it was a consolation to find the Nestorians settled at Cochin, which thus became a Portuguese stronghold, which their best soldier, Duarte Pacheco, held against a multitude. Calicut, where they began operations, has disappeared like Earl Godwin's estate. Forbes, who was there in 1772, writes: "At very low water I have occasionally seen the waves breaking over the tops of the highest temples and minarets." It was an international city, where 1500 vessels cleared in a season, where trade was open and property secure, and where the propagation of foreign religion was not resented.

The Zamorin, as they called the Rajah of Calicut, ended by taking part with the old friends from the Arabian Seas, who supplied his country with grain, against the visitors who came in questionable shape. The Portuguese lacked the diplomatic graces, and disregarded the art of making friends and acquiring ascendency by the virtues of humanity and good faith. When it came to blows, they acquitted themselves like men conscious that they were the pioneers of History, that their footsteps were in the van of the onward march, that they were moulding the future, and making the world subservient to civilisation. They were Crusaders, coming the other way, and robbing the Moslem of their resources. The shipbuilding of the Moors depended on the teak forests of Calicut; the Eastern trade enriched both Turk and Mameluke, and the Sultan of Egypt levied duty amounting to L290,000 a year. Therefore he combined with the Venetians to expel the common enemy from Indian waters. In 1509 their fleet was defeated by the Viceroy Almeida near Diu, off the coast of Kattywar, where the Arabian seaman comes in sight of India. It was his last action before he surrendered power to his rival, the great Albuquerque. Almeida sought the greatness of his country not in conquest but in commerce. He discouraged expeditions to Africa and to the Moluccas; for he believed that the control of Indian traffic could be maintained by sea power, and that land settlements would drain the resources of the nation. Once the Moslem traders excluded, Portugal would possess all it wanted, on land and sea.

Almeida's successor, who had the eye of Alexander the Great for strategic points and commercial centres, was convinced that sea-power, at six months from home, rests on the occupation of seaports, and he carried the forward policy so far that Portugal possessed fifty-two establishments, commanding 15,000 miles of coast, and held them, nominally, with 20,000 men. Almeida's victory had broken the power of the Moors. Albuquerque resolved to prevent their reappearance by closing the Persian Gulf and the Red Sea. With Aden, Ormuz, and Malacca, he said, the Portuguese are masters of the world. He failed in the Red Sea. When Socotra proved insufficient, he attacked Aden, and was repulsed. There was a disconcerting rumour that no Christian vessel could live in the Red Sea, as there was a loadstone that extracted the nails. Albuquerque succeeded in the Persian Gulf, and erected a fortress at Ormuz, and at the other end of the Indian world he seized Malacca, and became master of the narrow seas, and of all the produce from the vast islands under the equator. He made Goa the impregnable capital of his prodigious empire, and the work that he did was solid. He never perceived the value of Bombay, which is the best harbour in Asia, and did not see that the key of India is the Cape of Good Hope. His language was sometimes visionary. He beheld a cross shining in the heavens, over the kingdom of Prester John, and was eager for an alliance with him. He wished to drain the Nile into the Red Sea. He would attack Mecca and Medina, carry off the bones of the prophet, and exchange them for the Holy Sepulchre. The dependency was too distant and too vast. The dread proconsul in his palace at Goa, who was the mightiest potentate between Mozambique and China, was too great a servant for the least of European kings. Emmanuel was suspicious. He recalled the victorious Almeida, who perished on the way home; and Albuquerque was in disgrace, when he died on his quarter-deck, in sight of the Christian city which he had made the capital of the East.

The secret of Portuguese prosperity was the small bulk and the enormous market value of the particular products in which they dealt. In those days men had to do without tea, or coffee, or chocolate, or tobacco, or quinine, or coca, or vanilla, and sugar was very rare. But there were the pepper and the ginger of Malabar, cardamoms in the damp district of Tellicherry; cinnamon and pearls in Ceylon. Beyond the Bay of Bengal, near the equator, there was opium, the only conqueror of pain then known; there were frankincense and indigo; camphor in Borneo; nutmeg and mace in Amboyna; and in two small islands, only a few miles square, Ternate and Tidor, there was the clove tree, surpassing all plants in value. These were the real spice islands, the enchanted region which was the object of such passionate desire; and their produce was so cheap on the spot, so dear in the markets of Antwerp and London, as to constitute the most lucrative trade in the world. From these exotics, grown on volcanic soil, in the most generous of the tropical climates, the profit was such that they could be paid for in precious metals. When Drake was at Ternate in 1579, he found the Sultan hung with chains of bullion, and clad in a robe of gold brocade rich enough to stand upright. The Moluccas were of greater benefit to the Crown than to the Portuguese workman. About twenty ships, of 100 to 550 tons, sailed for Lisbon in the year. A voyage sometimes lasted two years out and home, and cost, including the ship, over L4000. But the freight might amount to L150,000. Between 1497 and 1612 the number of vessels engaged in the India trade was 806. Of these, ninety-six were lost. After the annexation by Philip II, Lisbon was closed to countries at war with Spain. Dutch and English had to make their own bargains in the East, and treated Portugal as an enemy. Their empire declined rapidly, and the Dutch acquired the islands long before the English succeeded on the mainland of India.

The Portuguese acknowledged no obligations of international law towards Asiatics. Even now, many people know of no law of nations but that which consists in contracts and conventions; and with the people of the East there were none. They were regarded as outlaws and outcasts, nearly as Bacon regarded the Spaniards and Edmund Burke the Turks. Solemn instruments had declared it lawful to expropriate and enslave Saracens and other enemies of Christ. What was right in Africa could not be wrong in Asia. Cabral had orders to treat with fire and sword any town that refused to admit either missionary or merchant. Barros, the classic historian of Portuguese Asia, says that Christians have no duties towards pagans; and their best writers affirm to this day that such calculated barbarities as they inflicted on women and children were justified by the necessity of striking terror. In the Commentaries of the great Albuquerque, his son relates with complacency how his father caused the Zamorin to be poisoned. These theories demoralised the entire government. S. Francis Xavier, who came out in 1542, found an organised system of dishonesty and plunder, and wrote home that no official in India could save his soul. By him and his brethren many converts were made, and as intermarriages were frequent, the estrangement grew less between the races. Just then, the Inquisition was introduced into Portugal, and sent a branch to Goa. One of the governors afterwards reported that it had helped to alienate the natives, whose temples were closed. But the solid structure of Almeida and Albuquerque was strong enough to defeat a second expedition from Egypt, after Egypt had become a province of Turkey, and an Indian war and insurrection. It declined with the decline of Portugal under Sebastian, in the latter part of the sixteenth century, but it perished through its association with Spain, at the hands of enemies not its own, and not from internal causes.

While the Asiatic empire was built up by the sustained and patient effort of a nation, during seventy years, the discovery of the West was due to one eager and original intellect, propelled by medieval dreams. Columbus had sailed both North and South; but the idea which changed the axis of the globe came to him from books. He failed to draw an inference favourable to his design from the driftwood which a tropical current carries to Iceland, and proceeded on the assurance of Pierre d'Ailly and of Toscanelli, that Asia reaches so far east as to leave but a moderate interval between Portugal and Japan. Although he rested his case on arguments from the classics and the prophets, his main authority was Toscanelli; but it is uncertain whether, as he affirmed, they had been in direct correspondence, or whether Columbus obtained the letter and the Chart of 1474 by means which were the cause of his disgrace.