The leading part in the resistance to the Moslem sea power was taken by Spain under Charles V. He had, as admiral of the navy, Andrea Doria, the Genoese, the ablest seaman on the Christian side. Early in his career he had captured a notorious corsair; later in the service of Spain, he defeated the Turks at Patras (at the entrance to the Gulf of Corinth), and again at the Dardanelles. These successes threatened Turkish supremacy on the Mediterranean, and Sultan Soliman "the Magnificent," the ruler under whom the Turkish empire reached its zenith, summoned the Algerian corsair Barbarossa and gave him supreme command over all the fleets under the Moslem banner. At this time, 1533, Barbarossa was seventy-seven years old, but he had lost none of his fire or ability. On the occasion of being presented to the Sultan, he uttered a saying that might stand as the text for all the writings of Mahan: "Sire, he who rules on the sea will shortly rule on the land also." The following year Barbarossa set out from Constantinople with a powerful fleet and proceeded to ravage the coast of Italy. He sacked Reggio, burnt and massacred elsewhere on the coast without opposition, cast anchor at the mouth of the Tiber and if he had chosen could have sacked Rome and taken the Pope captive. He then returned to Constantinople with 11,000 Christian captives. Charles V was roused by this display of corsair power and barbarity to collect a force that should put an end to such raids. Barbarossa had recently added Tunis to his personal domains, and the great expedition of ships and soldiers which the emperor assembled was directed against that city. Despite the warning given by the King of France, Barbarossa was unable to oppose the Christian host with a force sufficiently strong to defend the city. The Christians captured it and the chieftain escaped only by a flight along the desert to the port of Bona where he had a few galleys in reserve. With these he made his way to Algiers before Andrea Doria could come up with him. The Christians celebrated the capture of Tunis by a massacre of some 30,000 inhabitants and returned home, thanking God that at last Barbarossa was done for. Indeed, with the loss of his fleet and his newly acquired province it seemed as if the great pirate was not likely to give much trouble, but the Christians had made the mistake of leaving the work only half done.