WILLIAM II. (d. 1189), king of Sicily, was only thirteen years old at the death of his father William I. when he was placed under the regency of his mother, Marguerite of Navarre. Until 1171 the government was controlled first by the chancellor Stephen of Perche (1166-1168), and then 'by Walter Ophamil, ,archbishop of Palermo, and Matthew d'Ajello, the vice-chancellor. William's character is indistinct ; yet his reign is marked by an ambitious foreign policy and a vigorous diplomacy. Champion of the papacy and in secret league with the Lombard cities he defied the common enemy, Frederick II. In 1174 and 1175 he made treaties with Genoa and Venice and in February 1177 he married Joan, daughter of Henry II. of England. To secure peace with the emperor he sanctioned the marriage of his aunt Con stance, daughter of Roger II., with Frederick's son Henry, after wards the emperor Henry VI., causing a general oath to be taken to her as his successor in case of his death without heirs. This step, fatal to the Norman kingdom, was possibly taken that Wil liam might devote himself to foreign conquests. He now attacked
Egypt, but Saladin's arrival before Alexandria, forced the Sicilians to re-embark in disorder. On the death of Manuel Comnenus ( i8o), William took up the old design and feud against Con stantinople. Durazzo was captured (June 11, 1185), Thessalonica surrendered in August, and the troops then marched upon the capital; but were overthrown on the banks of the Strymon (Sept. 7, 1185). Thessalonica was abandoned and in 1189 William made peace with Isaac, abandoning all the conquests. He now planned to induce the crusading armies of the West to pass through his territories, and seemed about to play a leading part in the third Crusade. His admiral Margarito kept the eastern Mediterranean open for the Franks, and forced Saladin to retire from before Tripoli in the spring of 1188. In November 1189 William died, childless.