True, the small Spanish garrison still remained in Algiers, and because it was immured within a very strong fortress it held out. The time now came for this to be attacked with great vigour. For a period of fifteen days it was bombarded, and at length, after a most stubborn resistance, it was overcome. The stronghold was then pulled down, and Christian prisoners who in the summer season had rowed chained to their seats in the corsair galleys, were in the off-season employed to build with these stones the great mole to protect the harbour of Algiers from the western side. It was a stupendous undertaking, and seven thousand of these unhappy creatures accomplished the work in most of two years. Nothing succeeds like success, and the corsair prospered in power and possession to such an extent that he was pre-eminent. This naturally attracted to his dominion many thousands of other followers, and there was thus established not a mere small colony of pirates, but a grand corsair kingdom where the industry of sea-robbery was well organised with its foundries and dockyards, and with every assistance to agriculture, and a firm, hard government to keep the land in fit and proper cultivation. And now yet another invitation came to Kheyr-ed-din. Andrea Doria had defeated the Turks at Patras and in the Dardanelles. Like the policy of the corsairs, after each victory the Christian admiral employed the infidel captives to work at the oars of his galleys. Thus it was that the Sultan of Turkey—Solyman the Magnificent—realising that the Christian admiral was draining the best Turkish seafaring men, determined to invite Kheyr-ed-din to help him against Andrea Doria. So one of the Sultan’s personal guard was dispatched to Algiers requesting Barbarossa to come to Constantinople and place himself at the head of the Ottoman navy. Barbarossa accepted this as he had accepted other invitations, seeing that it was to his own interest, and in August 1533 left Algiers with seven galleys and eleven other craft. On the way he was joined by sixteen more craft belonging to a pirate named Delizuff, but before they had got to the end of the voyage Delizuff was killed in an attack on a small island named Biba. There followed some friction between the men of the deceased pirate and those of Barbarossa, and finally one dark night the ships of Delizuff stole away from Barbarossa’s fleet.