It is also from the Laurentian portolano of 1351 that we know how, at some anterior time, the greater group of the Azores had been found by Portuguese vessels under Genoese commanders. We find these islands also in the Catalan map of 1373, and in that of Pizigani of the same period (1367, 1373).
[Illustration: PART OF THE LAURENTIAN PORTOLANO.
It was in the reign of Edward III. of England that one Robert Machin, flying from England to avoid pursuit for stealing a wife, accidentally reached the island of Madeira. Here disaster overtook Machin's company, but some of his crew reached Africa in a boat and were made captives by the Moors. In 1416, the Spaniards sent an expedition to redeem Christian captives held by these same Moors, and, while bringing them away, the Spanish ship was overcome by a Portuguese navigator, Zarco, and among his prisoners was one Morales, who had heard, as was reported, of the experiences of Machin.
[Sidenote: Porto Santo and Madeira rediscovered.]
Zarco, a little later, being sent by Prince Henry of Portugal to the coast of Guinea, was driven out to sea, and discovered the island of Porto Santo; and subsequently, under the prompting of Morales, he rediscovered Madeira, then uninhabited. This was in 1418 or 1419, and though there are some divergences in the different forms of the story, and though romance and anachronism somewhat obscure its truth, the main circumstances are fairly discernible.
This discovery was the beginning of the revelations which the navigators of Prince Henry were to make. A few years later (1425) he dispatched colonists to occupy the two islands, and among them was a gentleman of the household, Bartolomeo Perestrello, whose name, in a descendant, we shall again encounter when, near the close of the century, we follow Columbus himself to this same island of Porto Santo.
It is conjectured that the position of the Azores was laid down on a map which, brought to Portugal from Venice in 1428, instigated Prince Henry to order his seamen to rediscover those islands. That they are laid down on Valsequa's Catalan map of 1439 is held to indicate the accomplishment of the prince's purpose, probably in 1432, though it took twenty years to bring the entire group within the knowledge of the Portuguese.