The conquest of Portugal and her empire by Philip II., in 1580, turned Spain into a Colossus bestriding the world, and it was inevitable that this world-dominion should be challenged by the other European states which faced upon the Atlantic. The challenge was taken up by three nations, the English, the French, and the Dutch, all the more readily because the very existence of all three and the religion of two of them were threatened by the apparently overwhelming strength of Spain in Europe. As in so many later instances, the European conflict was inevitably extended to the non-European world. From the middle of the sixteenth century onwards these three peoples attempted, with increasing daring, to circumvent or to undermine the Spanish power, and to invade the sources of the wealth which made it dangerous to them; but the attempt, so far as it was made on the seas and beyond them, was in the main, and for a long time, due to the spontaneous energies of volunteers, not to the action of governments. Francis I. of France sent out the Venetian Verazzano to explore the American shores of the North Atlantic, as Henry VII. of England had earlier sent the Genoese Cabots. But nothing came of these official enterprises. More effective were the pirate adventurers who preyed upon the commerce between Spain and her possessions in the Netherlands as it passed through the Narrow Seas, running the gauntlet of English, French, and Dutch. More effective still were the attempts to find new routes to the East, not barred by the Spanish dominions, by a north-east or a north-west passage; for some of the earlier of these adventures led to fruitful unintended consequences, as when the Englishman Chancellor, seeking for a north-east passage, found the route to Archangel and opened up a trade with Russia, or as when the Frenchman Cartier, seeking for a north-west passage, hit upon the great estuary of the St. Lawrence, and marked out a claim for France to the possession of the area which it drained. Most effective of all were the smuggling and piratical raids into the reserved waters of West Africa and the West Indies, and later into the innermost penetralia of the Pacific Ocean, which were undertaken with rapidly increasing boldness by the navigators of all three nations, but above all by the English. Drake is the supreme exponent of these methods; and his career illustrates in the clearest fashion the steady diminution of Spanish prestige under these attacks, and the growing boldness and maritime skill of its attackers.