It had taken the Hautevilles nearly a century to establish the maritime empire that Roger II bequeathed to his successors. It took those successors only a few decades to fritter it away. By 1194, the Hauteville dynasty was at an end, replaced by the German House of Hohenstaufen. There are, of course, myriad reasons why this occurred, but the most salient single answer is: Roger's heirs deviated from the core naval strategy that he had so painstakingly developed, a strategy that focused on dominance of the central Mediterranean. Gradually, the last Hautevilles lost their grip on the north and south shores of the ‘middle sea’; they allowed their adversaries to ally with the great Italian sea powers of the age; and, worst of all, they exhausted their naval power on ill-advised adventurism in distant lands, eventually allowing the once-daunting Sicilian fleet to fall into desuetude. Each succeeding sovereign contributed his own peculiar set of blunders to the tragic decline.

Naval operations of William I

Prior to his demise, Roger II did everything he could to prepare William, his only surviving son, for what he knew would be a difficult reign. He even gave him a head start on his regal duties by having him crowned co-sovereign on Easter Sunday 1151. But he could not give him the one advantage that he himself had enjoyed for most of his rule and what his son needed most: an advisor of the caliber of George of Antioch.