As the Portuguese exploration of the African coast proceeded during sixty years, the objects with which it was pursued were almost completely transformed; and it illustrates perhaps more aptly than any other episode in European history the transition from the ideas of the crusading age to those of the age of dominant commerce and colonisation. Dom Henrique’s conception of a “ Greater Portugal” including the island groups of the Atlantic and Bilad Ghana on the Senegal River certainly recalls, and was probably founded on, the Mohammadan dominion which included Southern Spain, the Balearic Islands, and Northern Africa, and which St Louis proposed to replace by a Christian dominion equally comprehensive. To this strictly medieval conception the Iffante added some dim idea of a junction with the Christian sovereign of Abyssinia, to be effected by ascending the Western Nile. Beyond this point we have no reason to conclude that his imagination ever wandered. The transformation began after his death. The new dominion called “Guinea” was ascertained by a rapidly extending process of exploration to be of enormous size; this modest province, as it had seemed in prospect, assumed the proportions and character of a vast and hitherto unknown continent. Twenty-six years of discovery, after the Iffante’s death, revealed three times the length of coast which had been made known in the course of a considerably longer period during his lifetime; and the Portuguese sailors had now been brought within measurable distance of the Red Sea and Persian Gulf of India, China, and the Spice Islands. Europe’s commerce with the East-an object far exceeding in importance the conquest of Guinea-was evidently within the grasp of Portugal. Ten years elapsed, and a transcendent effort of seamanship had to be made, before actual possession was taken of the prize. Meanwhile, the geographical knowledge attained during these twenty-six years wrought like a ferment in the minds of European observers. It was felt that the little kingdom of Portugal had effected something like a revolution in the intellectual world: and the ideas inspired by this change, while the existence of the New World, called afterwards America, was as yet unsuspected, are admirably expressed in an epistle addressed to Joao II by Angiolo Poliziano, professor of Greek and Latin literature at Florence. The foremost scholar of the Renaissance tenders to the Portuguese King the thanks of cultivated Europe. Not only have the Pillars of Hercules been left behind, and a raging ocean subdued, but the interrupted continuity of the habitable world has been restored, and a continent long abandoned to savagery, representing one-third of the habitable world, has been recovered for Christianity and civilisation. What new commodities and economic advantages, what accessions to knowledge, what confirmations of ancient history, heretofore rejected as incredible, may now be expected! New lands, new seas, new worlds (alii mundi), even new constellations, have been dragged from secular darkness into the light of day. Portugal stands forth the trustee, the guardian, of a second world (mundus alter), holding in the hollow of her hand a vast series of lands, ports, seas, and islands, revealed by the industry of her sons and the enterprise of her Kings. The purpose of Politian’s epistle is to suggest that the story of this momentous acquisition should be adequately written while the memorials of it are yet fresh and complete, and to this end he offers his own services. Its significance for ourselves lies in the fact that his admiration is couched in terms which would apply with equal or greater propriety to the impending discovery of the western continent. The existence of America was as yet unsuspected : and the mental fermentation produced in Europe by the Portuguese voyages quickly led to its discovery. To cosmographers this fermentation irresistibly suggested the revival of an idea evolved eighteen hundred years previously by Greek geographers from the consideration of the recently ascertained sphericity of the earth and the approximate dimensions of its known continental areas. A few days1 sail, with a fair wind, it had been long ago contended, would suffice to carry a ship from the shores of Spain, by a westward course, to the eastern shores of Asia. The argument had never been wholly lost sight of; and the revival of science in the thirteenth century had once more brought it into prominence. Roger Bacon had given it a conspicuous place in his speculations as to the distribution of land and ocean over the globe. One is even tempted to think that those adventurous Genoese who in 1281 passed the Straits of Gibraltar with two vessels, intending to make their way to the Indies, and were never again heard of, prematurely sought to bring it to the test of experience; but the better opinion is that they merely proposed to circumnavigate South Africa. As the African coast was progressively explored by the Portuguese and laid down on the chart, the realisation of the idea of reaching the East by way of the West became a practical matter. While Gomes was pushing forward the exploration of Southern Guinea, a canon of Lisbon, on a visit to Florence, consulted Toscanelli, the most celebrated of Italian physicists, on the feasibility of such a voyage, and brought back to Affonso V a verbal opinion favourable to it; and this opinion was shortly confirmed by a letter and a chart on which the proposed westward course was laid down. Twelve years were yet to pass before Diaz reached the Cape of Good Hope; the time for testing the scheme had not fully come. But as the Portuguese ships drew nearer to their goal, the western voyage more and more attracted attention; and the idea gained countenance through the extension of maritime enterprise further and further into the unknown westward expanses of the Atlantic Ocean, pursuant to the development of a Greater Portugal according to Dom Henrique’s design.
Before his death the Ift’ante had provided for colonisation and church-building in each island of the Azores group. Beyond the Azores, medieval imaginative cartographers dotted the unknown Atlantic with numerous islands, some of which were distinguished by positive names. Scholars pondered over Pliny’s account, based on a legend stated at length in Plato’s Timaeus, of the great island Atlantis, believed to have formerly existed far to the westward of Mount Atlas, from which both island and ocean derived their familiar name. Later legends described various existing islands as having been actually reached in historical times. Arab sailors had discovered the “ Isle of Sheep”; Welsh emigrants had peopled a distant land in the west; seven bishops, fleeing before the Mohammadan invaders, had sailed westward from the Spanish peninsula and founded Christian communities on an island which thenceforward bore the name of the Isle of the Seven Cities. Saint Brandan, an Irish missionary, had reached another rich and fertile island, traditionally named from its discoverer; another island, believed to lie not far to westward of