28. But sixty cities and towns were now in revolt, and, unless they were recovered, Philip could no longer be considered the king of the Netherlands. Nothing was left but the slow process of siege operations. Haarlem held out seven months, and cost the Spaniards ten thousand men. It surrendered at last under the promise of an amnesty to its defenders, when they were murdered by thousands in cold blood. But Philip was dissatisfied with Alva for his slow progress, and for his execution of Catholics as well as Protestants; and in 1753, after five years' rule, he recalled him, and, with characteristic ingratitude, neglected and ill-treated him for his faithful but bloody services. 29. Don Luis Requesens succeeded the Duke of Alva as governor of the Netherlands and as commander of the Spanish army. While a zealous Catholic, he seems to have been a much more humane and just man than Alva. He began his administration by abolishing the most obnoxious measures of his predecessor, thus changing the whole tone of the government. Had he been left to follow his own counsels in everything, he doubtless would have come to an understanding with the Prince of Orange, and established peace upon a permanent basis. But the king was obstinately determined to capture the revolted cities and punish his rebel subjects, and the general was obliged to continue the war. At this time William was besieging Middleburg, on the island of Zealand, and one of the first acts of the newly-appointed, governor was to raise the siege. To this end he caused a large fleet to be assembled, and under the command of two experienced admirals he sent it down the Scheldt to the relief of Middleburg. The Prince of Orange immediately hastened to the critical spot, and gave direction to patriot operations. The Holland ships were collected, and a great naval battle took place on January 29, 1574. Although their force was much the greater, the Spaniards had little chance upon the water in a contest with the half-amphibious inhabitants of the Low Countries. The smaller vessels of the Prince of Orange fell upon the Spanish fleet with a ferocity which they could not withstand, and the result was a complete victory, with the destruction of their principal vessels. Middleburg soon after surrendered to the patriots, and the sway of William over the maritime provinces was rendered complete.