Before starting on this expedition Kheyr-ed-Din had made an innovation in the manning of some of the most powerful of his galleys, which was of the utmost importance, and which was to add enormously to the success of his future maritime enterprises. The custom had always been that the Ottoman galleys had been rowed by Christians, captured and enslaved; of course the converse was true in the galleys of their foes. There were, for the size of the vessels, an enormous number of men carried in the galleys of the sixteenth century, and an average craft of this description would have on board some four hundred men; of these, however, the proportion would be two hundred and fifty slaves to one hundred and fifty fighting men. That which Kheyr-ed-Din now insisted upon was that a certain proportion of his most powerful units should be rowed by Moslem fighting men, so that on the day of battle the oarsmen could join in the fray instead of remaining chained to their benches, as was the custom with the slaves. It is, however, an extraordinary testimony to the influence which the corsair had attained in Constantinople that he had been able to effect this change in the composition of some of his crews; it must have been done with the active co-operation of the Sultan, as no authority less potent than that of the sovereign himself could have induced free men to undertake the terrible toil of rower in a galley. This was reserved for the unfortunate slave on either side owing to the intolerable hardship of the life, and results, in the pace at which a galley proceeded through the water, were usually obtained by an unsparing use of the lash on the naked bodies of the rowers. This human material was used up in the most prodigal manner possible, as those in command had not the inducement of treating the rowers well, from that economic standpoint which causes a man to so use his beast of burden as to get the best work from him. In the galley, when a slave could row no more he was flung overboard and another was put in his place. The admiral, however, even when backed by the Padishah, could not man a large fleet of galleys with Moslem rowers, and, as there was a shortage in the matter of propelling power, his first business was to collect slaves, and for this purpose he visited the islands of the Archipelago. The lot of the unhappy inhabitants of these was indeed a hard one. They were nearer to the seat of the Moslem power than any other Christians; they were in those days totally unable to resist an attack in force, and in consequence were swept off in their thousands.