Barbarossa was terrified at the successes of Charles V. With the Gouletta he lost eighty-seven galleys, and more than three hundred pieces of bronze ordnance, inclosed in that citadel. He held a council with the Turks, and pointed out to them the dangers to which they were exposed. They had two enemies equally to fear,--the inhabitants and the Arabs, who detested their domination; the twenty-five thousand Christian slaves in Tunis must necessarily be expected to revolt, and open the gates to the Spaniards. With regard to these slaves, he declared he was resolved to put them all to death. Sinan the Jew represented to Barbarossa that he would render himself odious to all nations; that he would lose the ransom of the most considerable of the slaves, and that he must not have recourse to such a cruel measure till the last extremity. Barbarossa consented to suspend the horrible project he had formed; but he had the slaves loaded with fresh chains, shut them up in the castle, and placed under them a number of barrels of gunpowder. He passed the rest of the night in an agony of fear and hope, and in expectation of the day which was to decide his fate. He left Tunis the next morning, at the head of eighty thousand men, and encamped in a plain a full league from the city. The two armies were soon in face of each other. The Arabs at first attacked the Christians with great spirit; but scarcely had they sustained the first discharge of the artillery, than they broke their ranks, and drew with them the Moors, and even the Turks. Barbarossa did his utmost to rally them, but they were deaf to his voice, and only took counsel of the terror with which they were seized. Barbarossa, trembling with rage, sounded a retreat, rallied the fugitives, and passed the night under arms beneath the walls of the city. Whilst he was deliberating if he should go again and offer battle to the Christians, or shut himself up in Tunis, some Turks came to inform him that the slaves had broken their chains, and had made themselves masters of the castle. Barbarossa hastened thither, and was met by musket-shots and a shower of stones. Transported with fury, he cried out that all was lost, as the slaves were masters of the castle and of his treasures. He immediately left Tunis at the head of a body of Turks, and contrived to place himself in safety.