In the middle of the fifteenth century Portugal was engaged in a truceless war with the Moors of North Africa. In this, the little country was only taking a part in the general war between Christians and Mahomedans that was waged all along the Mediterranean from east to west. Spain also took part in it, and so did Genoa and Venice, and the Knights of St. John at Malta, and even little England away in the rear of Christendom, sent her troops to defend the frontier. In those days Christendom was one nation, with one emperor and one pope, and all the European peoples knew that the war concerned not the part but the whole. For the Crescent had penetrated into Europe as far as France, and the Holy Sepulchre, which was then the shrine of all Christians, was in the hands of the Infidels.

In their part of the battlefield the Portuguese carried on a desperate war. They sent army after army into the north of Africa, they took the Moorish town of Ceuta, but they were beaten back from the walls of Tangier. Scimitar against sword, both sides fought with desperate valour, and the deeds of the heroes are still remembered in song and legend. On the Christian side, among the chief of these paladins was Prince Henry, one of the Royal Infants of Portugal. We hear of him holding the gate of Ceuta against a thousand Infidels; but in the end the power of the Crescent was too strong for him. He was gradually driven back, and was forced to return to his country, leaving his brother, the brave Prince Ferdinand, a prisoner in the hands of the Infidels. The Moors offered to set free their royal prisoner if Portugal would restore to them their town of Ceuta, and the king, torn between his duty and his love, asked all the other princes of Christendom what he should do. They replied that never must Christian town be surrendered to the Infidel for the poor body of one man, and Prince Ferdinand was left to die in the Sultan's dungeons.

His brother, Prince Henry, known to history as the Navigator, was struck with an almost mortal grief at this calamity. He withdrew himself from the sight of all men, and lived like a hermit on the barren Cape of St. Vincent.

But great thoughts were forming in his mind as he looked over the unknown sea. When he sacked the town of Ceuta his soldiers had rolled great jars of honey and wine and oil and spices into the streets, and had found wonderful treasures of stuffs and drugs, gold and silver and gems. Then Prince Henry realised that it was the wealth of the Moslems that made them strong, and he knew this wealth came from India. For in those times the whole trade of the East, its sugar and spices, its nutmegs and cloves and cinnamon, its silks and brocades, its pearls, and porcelain, and myrrh, and frankincense, all came to Europe overland from the Persian Gulf and the Red Sea to Constantinople and Cairo. The Mahomedans levied heavy toll upon this merchandise before they allowed it to be carried to Europe in the ships of Venice and Genoa, and so they obtained the wealth which made them a danger to all Christendom. Not only did they levy toll on the merchandise, but the whole trade of Asia was in their hands. Arab ships alone sailed the Indian Ocean and took over the cargoes of Chinese junks at Singapore, and Arab caravans crossed the desert with these same cargoes to the Moslem custom-houses of the Mediterranean and the Golden Horn.

This Prince Henry knew, and he knew that so long as the Mahomedans held this trade the Crescent would be strong. But he had heard of two things which gave him hope. He had heard that behind the Infidels in the centre of Africa, in the land from which the Nile flowed, there was a Christian country governed by a Christian king called Prester John. This Prester John was a monarch so great that all India paid him tribute, and it was said that if he liked he could drain the Nile and ruin Cairo. He lived in a land of gold and fire; the anthropophagi, with heads beneath their shoulders, were among his subjects; he received as tribute the carbuncles which the poison-breathing Indian dragons wore in their heads; he was an all-powerful Christian monarch, and if Portugal could make him her ally the strength of the Infidel would certainly be crushed as between the two arms of a nutcracker.

Then Prince Henry had also heard that there was a seaway round the south of Africa to India. How this fact came to be known is a mystery to us. Perhaps the Carthaginians had found their way round in olden times, and the tradition was handed down through the centuries. Perhaps European travellers had visited the Arab settlements away far south on the east coast of Africa, or heard East African traditions of the shape of the Continent. However it came about, we know that in the middle of the fourteenth century, a hundred and forty years before the Cape of Good Hope was discovered, there existed a map (in the Medicean Atlas which is still to be seen in the Laurentian Library in Florence) showing the general shape of Africa, including the Gulf of Guinea and the way round the Cape to the Indian Ocean. Prince Henry, therefore, nursed the hope that he might get into the Indian Ocean by way of the South Atlantic, and so win for Portugal the wealth which was now providing the war funds of the Saracens. Prince Henry was, in fact, on the true scent where Christopher Columbus was on the false.

The prince was a very wise and patient man. He built a college and observatory on his barren spit of sand, and collected there the wisest scholars, the most learned books, and the latest scientific instruments of his time. He read such works as the travels of Marco Polo, of Jordanus of Severac, and Macudi the Moor, and here were gathered such men as Master Jacome of Majorca, deep in all the arts of navigation and the making of maps, Abraham Zakut the Jew, who demonstrated the value of the astrolabe, and many other Christian, Jew, and Arab scholars skilled in the mysteries of mathematics and astronomy.

It was a painful task to sift truth from fable in those times, and Prince Henry, very likely, believed that the earthly paradise came between India and the land of Prester John, and many other fables which seem equally absurd nowadays. But he held fast by every truth he discovered, and worked with untiring zeal. In his port of Lagos he built ships, and built them so well that the great shipbuilder, Cadamosto the Italian, whom he employed, was able to say that the caravels of Portugal were better than the best that Genoa could produce. In his college of Sagres he trained sailors in the use of the astrolabe, which took the height of the sun, and the compass, which pointed to the Pole, and he launched fleet after fleet on the Western Ocean to go south in search of the passage of which he dreamed.

Now the Atlantic was then an almost unknown ocean, and the Arabs—perhaps from guile, perhaps from superstition—spread abroad all manner of dreadful stories about the Green Sea of Darkness, as they called it. They said it was full of sea-monsters and serpent-rocks and water-unicorns, that in the tropics the sun poured down sheets of liquid flame and kept the water boiling hot day and night, and that from the waves Satan himself stretched a great black hand ready to seize the first sailor who should venture thither. But Prince Henry was not to be deterred. He obtained a dispensation from the Pope to protect the souls of sailors from these dangers and to ensure them Paradise if they should die upon the voyage; and his caravels, with the Cross upon their sails, went every year farther and farther south. On they went, past the Grand Canary and past Teneriffe, as far as Cape Bojador. For long they dared not venture farther, so dread-inspiring were the stories the Moors spread abroad; but at last, urged by their Prince, they doubled the Cape and came back gleefully with the news that the waters beyond were as easy to sail in as the sea at home, and that on the shores they had so much dreaded they gathered the flowers called in Portugal St. Mary's Roses.

But then the sailors came upon the slaves and gold of Guinea, and greed made them deaf to all Prince Henry's prayers. I do not want gold, I want knowledge," he would say, as they returned with rich cargoes. "Plant the Cross on a new headland, that is what I want." But the work went on slowly, and the great prince died without seeing the fulfilment of his dreams.

To show how curiously superstition and religion are mixed up with this great discovery, let me tell a story of Prester John. Ambassadors were brought in Portuguese ships from the kingdom of Benin to the court of King John of Portugal, and they told him that beyond their country, far up on a mighty river, lived a great king called Ogane, who was held in high veneration by the people of Benin. So much did they venerate him that their kings could not reign without his consent, and when their ambassadors went to visit him they were only allowed to see his foot, which was stretched out from behind a curtain. As a sign of his favour, they were given a helmet of brass and a metal cross, which they took back to Benin in triumph. Now this mention of a cross led King John to believe that Ogane was no other than the great Christian monarch Prester John, and the information spurred him on to a tremendous effort.

One of his captains, Duarte Pacheco by name, was sent to seek Prester John by way of the dark fever-haunted rivers which flow into the Gulf of Guinea; two envoys, Afonso de Paiva and Pedro Cavilhao, were to go circumspectly in search of India and Prester John by an eastern route through Alexandria and Cairo; certain ships were to sail north and endeavour to find a north-east passage to China; and last, and most important to us in this great adventure, Bartholomew Diaz was commanded to sail south by the west coast of Africa until he should come to the end of the land, and so by the south sea to India.

Thus, in 1486, Diaz set forth on this mighty enterprise—fraught with consequences as great to the world as the voyage of Christopher Columbus itself. He had only two small ships of but fifty tons burthen, with a tender to carry such necessaries as might afterwards be required. With this meagre equipage he went boldly forward, passing the crosses which had been set up like milestones along the coast. The Gulf of Guinea, with its torrid languid air and oily water and shores of man-grove swamps, was left far behind. The coast became parched and barren and desolate. But Diaz went on, halting only now and then to land negroes and negresses, who were despatched like carrier-pigeons with messages for Prester John. At last even the cross that Diego Cam had planted near St. Helena Bay, the farthest point hitherto reached, was left behind, and Diaz beat round the Cape of Good Hope itself, then wrapt in storms, and so burst into a sea never before sailed by any man. Then he coasted along the southern shores of Africa, on the great road the ships of so many nations have sailed since. He had now—if he had only known it—the secret almost solved; but the storms never ceased, the food and water were nearly at an end, and the tackle of the ships was much worn by wind and weather. The officers and sailors came near to open mutiny; but the captain still persisted until he reached and passed the island of Santa Cruz in Algoa Bay, near where Port Elizabeth now stands. Twenty-five leagues farther, and his officers at last constrained him to turn back, after placing a cross on the island, to which, as the old chronicler tells us, he bade farewell with as much grief as if he were leaving a son in exile for ever.

So Diaz went sorrowfully home, stopping at Cape Point to erect the Cross of San Filippe.

On his way north he found Duarte Pacheco sick almost unto death on the coast of Guinea. He had done his best to find a riverway to Prester John: but in the dark channels and swamps of mangrove trees, where no sea comes through, and the roots are like black serpents writhing in the slime, the fever-demon seized him and he narrowly escaped with his life.

And Diaz also found his tender where he had left it—though some of its crew were dead, and the rest so weak that one of them died with joy at the sight of the ships.

So Diaz came back to Portugal with the news; and it is said that when he told the king of the great southern promontory which he had called the Cape of Storms, the king commanded that the name should be changed to the Cape of Good Hope, because, no doubt, he saw that it was the turning-point on the road to India.

All this time Cavilhao and de Paiva were exploring in the east and seeking news of Prester John. The two chose different roads, and Cavilhao went from Egypt through Arabia towards India. He got to Aden with some Moors of Tremicem and Fez, and thence he took ship for Calicut, the great port in those days of the Malabar coast. Here he saw vast fleets of Arab ships, and learned the secrets of the Indian trade. Thence he sailed across the Indian Ocean to the east coast of Africa, and saw Mozambique and Sofala. And he passed north again and got to Cairo, where he found that de Paiva was dead. But he met two Jews of Portugal, Rabbi Hebrao of Beja and Rabbi Josephe, a shoemaker of Lamego, and by one of them he sent a letter to the king—one of the most important letters ever written in the whole history of the world. He told his master of the riches of India and the caravans of camels that passed from Ormuz and Aden to Cairo, and the golden cities of Aleppo and Damascus. And then he wrote these portentous and prophetic words, which helped to shape the destinies of the world:—

"Keep southward: if you persist Africa must come to an end. And when ships come to the Eastern Ocean, let them ask for Sofala and the Island of the Moon (Madagascar), and they will find pilots to take them to Malabar."

So he wrote, but he himself never went home. Instead, he turned his steps south and went up the Nile till he came to the kingdom of Prester John, who was no other than the Negus of Abyssinia, where he was made a great noble and abode all his life.

Thus between Cavilhao on the east and Diaz on the west the riddle was as good as solved. There only wanted the keystone to the arch, the last link to the chain, the passage from Algoa Bay to Sofala. This Vasco da Gama supplied, and won riches and honour and fame; but Diaz, who was greater than he, has for monument the bubbling waves of the South Atlantic, where he lies near the country of Brazil, of which he and Pedro Alvares Cabral made discovery.