There were obvious geographical and historical reasons why the kingdom of Portugal should furnish the important series of incidents in the expansion of geographical knowledge which now claims attention. The Arab power in the Iberian peninsula had been broken, and the Portuguese monarchy had established itself during the twelfth century. The Arab mantle of the explorer descended upon Portuguese shoulders. The small kingdom has a large extent of coastline; and not only is communication with Europe by land through the passes at either end of the Pyrenees comparatively difficult, but between those passes and Portugal were Spanish states, with which Portuguese relations were by no means amicable. Thus there was little opportunity for the commercial expansion of Portugal except over-seas.

The first important figure in the history of this expansion is that of Prince Henry, surnamed the Navigator (1394–1460), fifth son of King John I. His objects were to extend Portuguese commercial interests mainly in West Africa, and also, it would appear, to discover new lands, if they were to be discovered, to the west of those Atlantic islands which formed the limit of knowledge to the west from very early times. Even the knowledge of the islands themselves was indefinite enough; so that when, in or about 1415, Henry began52 sending his seamen to the Canaries and later to the Madeira and the Azores, he was inspiring, if not actual discovery, at any rate the acquisition of largely new information. Between 1415 and 1431 colonization and trade had already begun to be established in some of the islands; and, though the Portuguese navigators did not forestall Columbus, it is likely that they conceived the possibility of a westward route to the Far East. Prince Henry’s residence from 1438 to 1460 was Sagres, which consequently became a centre for geographical research, for he gathered about him expert cartographers and instructors for his navigators, whom he supplied with the best obtainable instruments, maps, and information: he used not only European but also Arab sources. With regard to the West African coast, he experienced some years of comparative failure; but from 1444 explorations here were rapidly extended, and a few of the leading navigators and explorers who worked under Prince Henry’s direction and after his death may be mentioned. In 1443 John Fernandez travelled inland in the district of Rio de Oro, and collected valuable information about the resources, physical conditions, and people of the south-west part of the Sahara. He made further journeys in 1446–47. Diogo Gomez, in 1448, made his way up the Gambia river. Alvise Cadamosto, a Venetian in Prince Henry’s service, was working in 1455 south of the Senegal; and in 1456 he visited, and probably actually discovered, the Cape Verde Islands. His accounts of his voyages were full and valuable, and he also dealt with the explorations of Pedro de Cintra, in 1461 or 1462, to Sierra Leone and the Gold Coast. Gomez made a voyage to the Cape Verde Islands in 1462; but he is most notable as chronicler of the life-work of Prince Henry.

53 King John II built on the prince’s foundations. In 1482 he sent out Diogo C?o, who discovered the Congo and ascended it for a short distance, and subsequently saw the coast of Angola as far as 13° 26′ S. at Cape Santa Maria. On a second voyage (1485–1486) he penetrated still further south, to Cape Cross. He erected pillars at various points on the coast—a practice followed by some of his successors; and some of these monuments have been found and preserved. In a voyage in 1486 or 1487–88 Bartolomeu Diaz extended the knowledge of the west coast nearly five degrees beyond C?o’s furthest, reaching 26° 38′ S. He was then driven south by high winds and storms, turned east, and found no land; he therefore steered north again, and struck the coast of what is now the Cape Province at Mossel Bay. Continuing eastward, he reached the Great Fish River, and was able to realize that the coast was now trending north-easterly, and that the southernmost point of the continent had been turned; but his crew were surfeited with their dangers, and insisted on returning. The important cape which he had discovered he is generally stated to have named Cabo Tormentoso, the Cape of Storms; and the story goes that King John, recognizing the importance of the discovery to the future object of a sea-route to the East, changed the name to the Cape of Good Hope. But there is good reason to believe that the happier name was given by Diaz himself. It had been one of the wishes of Prince Henry, and was one of the objects of the voyage of Diaz, to establish communication with a Christian king of whose powers rumours reached the west coast of Africa from the interior, and who was known under the name of Prester John. In 1487 Pedro or Pero de Covilh?o and Alphonso Payva were sent,54 partly with the same object, by way of the Mediterranean. They visited Egypt, and after many wanderings came to Aden, whence Covilh?o proceeded to Calicut and Goa in India, and, returning thence, travelled south along the East African coast as far as Sofala. He then journeyed in the coast lands of Arabia, and visited Mecca and Medina, and finally, entering Africa, proceeded to the court of Prester John in Abyssinia, where he was well treated, but from which he was never allowed to return home. Payva, meanwhile, had travelled into Ethiopia, and had died there.

The journey to India by way of the Cape of Good Hope was completed in due course in the last decade of the century; but earlier in that same decade the New World had been discovered by Columbus, and the era opened by these two tremendous incidents may be more fittingly considered in the following chapter; while for the moment some consideration may be given to the state of cartography and theory at the time when Columbus was planning his voyage.

The works of Ptolemy can have been known to few in the original Greek at this time, and for many centuries before. When, therefore, the translation of his Geography into Latin, originally undertaken by Emanuel Chrysoloras, a Byzantine scholar who settled in Italy, was completed in 1410 by his pupil Jacobus Angelus, these two students lit a beacon in the course of geographical study. The translation, which is usually identified with the name of Angelus alone, was issued under the title of Cosmography instead of Geography. It would appear that Angelus, of whose life apart from this work little is known, not only dealt with the text, but also did the maps into Latin. In a short time there was no lack of copies of the work, and it was soon55 found necessary to add to the maps at certain points where they failed to represent knowledge which was by this time in possession of the translators. Already about 1424 Claudius Clavus Swartha had constructed in Italy a map which showed the north-westward extension of knowledge as far as Greenland; the curious orderly curves by which the coastlines are represented frankly acknowledge the draughtsman’s lack of detail. About 1470 Nicolaus Germanus, often known erroneously as Donis, produced a manuscript edition of Ptolemy, with maps magnificently illuminated and on improved projections. He also added new maps, and it has been said of the collection that, as far as concerns methods of drawing, it is the prototype of all subsequent atlases (Nordenskj?ld). An edition, probably of 1472, if not later, though it is dated earlier, reveals the use of a conical projection with meridians and parallels drawn across the maps; and, as points of some interest in comparison with modern maps, it may be added that the seas are green, the mountains blue, and other parts of the land red and yellow. The Florentine edition in verse, of about 1480, by Francesco Berlinghieri, contained an important series of new printed maps, including Italy, France, Spain, and Palestine.

Although the extension of knowledge to the north-west, as has been mentioned, attracted considerable attention on the part of the editors of Ptolemy, the recent Portuguese discoveries in West Africa did not, apparently, do the same. In an edition, for instance, of 1486, made at Ulm, a geographical description of the north-west lands, including Greenland, was furnished, and there were quoted the latitude and longitude of 183 places in northern Europe and Greenland; but56 there was no evidence that the conception of the southern limit of the habitable world by Ptolemy was understood to be now proved wholly erroneous by the Portuguese discoveries.

On the other hand, the appreciation of Portuguese labours appeared earlier, as was natural, in Portolano maps. That of Andrea Bianco (1448) drew probably on a Portuguese original, showing the West African coast as far as Cape Verde. On the world map of Fra Mauro, already referred to, the Portuguese discoveries are mentioned in an inscription of considerable length.

In connection with prevailing ideas as to what lands lay in the Atlantic beyond the certain knowledge of men, it may be observed that the conception of a continent or island of Atlantis was very old, and there were other mythical lands which were also given places in distant parts of the ocean. Portolano maps of the fourteenth and fifteenth centuries show the island of Brazil lying to the west of Ireland, an island named Mam to the south of Brazil, and, still further away in the ocean, and to the south again, a large island in the form of a parallelogram, which bore the name of Antillia, and appears as early as 1426.

The sphericity of the earth, as has been seen, was revived as a theory by Bacon and Albertus; and to these inquirers may now be added the name of Cardinal d’Ailly (d. 1422), whose work, entitled Imago Mundi, may be mentioned because it is known to have been in the possession of Columbus. His copy still exists.

A name closely identified with Columbus’s preconceived ideas as to the voyage to the Indies by way of the western ocean, and his efforts to obtain recognition for them, is that of Paolo del Pozzo Toscanelli (1397–1482), a Florentine mathematician, astronomer, and57 cosmographer, whose advice was asked by King Alphonso V. of Portugal as to the probability of this western route. He sent the king a statement and a chart in support of Columbus’s ideas. The chart is lost; but the author describes it as showing the Indies opposite and to the west of Ireland and Africa, together with the islands which were known to lie off the coast of the Asiatic mainland, and certain known landing places. A globe made in 1492 by Martin Behaim, of Nuremberg, is usually cited as giving the best existing representation of the views as to the extent of the Atlantic, and the route across it, at the moment when Columbus began his first voyage. Behaim had lived in Portugal, and had a high scientific reputation at court. He had probably visited the more northerly parts of the west coast of Africa and also the Azores, though he claimed to have a much more extensive first-hand knowledge, as having accompanied Diogo C?o. It is doubtful if he did so; but if he did, he made but little use of his opportunity. His representation of the west coast of Africa is not accurate; and for the rest, although he had the chance, and apparently an unusually favourable one, of carrying the results of Portuguese research into Europe, he made poor use of it. He was obsessed by Ptolemaic ideas; he showed in a modified form the old south-eastward extension of Africa, with Madagascar and Zanzibar as two great islands lying off it, Zanzibar being south of Madagascar. He also modified, but still retained, the Ptolemaic idea of the non-peninsular form of India and the exaggerated size of Ceylon. He gave a gross representation of the Malay Peninsula, and in general ignored Marco Polo’s results, and those of other Asiatic travellers. His58 representation of Scandinavia was indifferent, and even that of the Mediterranean was below the level of the Portolano maps. As regards the width of the Atlantic Ocean between Europe and Asia, he appears to have followed Toscanelli; and he showed the mythical island of Antillia and also that of St. Brandon (the existence of which on maps was an outcome of the fabled wanderings of a holy man of Ireland in the sixth century) in mid-ocean between the Euro-African and the Asiatic coasts.

Such was the view of the ocean barrier which lay between Columbus and the attainment of his ideal. It serves as a reminder, which, in view of the results he obtained, is sometimes necessary, that that ideal was the discovery, not of new lands, but of a new route to lands already known.