The Tomb of William II in the Duomo of Monreale, March 2005

William II (1153–1189), called the Good, was king of Sicily and Naples from 1166 to 1189.

William was only thirteen years old at the death of his father William I, when he was placed under the regency of his mother, Margaret of Navarre.

Until the king came of age in 1171 the government was controlled first by the chancellor Stephen du Perche, cousin of Margaret (1166–1168), and then by Walter Ophamil, archbishop of Palermo, and Matthew of Ajello, the vice-chancellor.

William's character is very indistinct. Lacking in military enterprise, secluded and pleasure-loving, he seldom emerged from his palace life at Palermo. 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 was able to defy the common enemy, Frederick I Barbarossa. In 1174 and 1175 he made treaties with Genoa and Venice and his marriage in February 1177 with Joan, daughter of Henry II of England and Eleanor of Aquitaine, marks his high position in European politics.

In July 1177, he sent a delegation of Archbishop Romuald of Salerno and Count Roger of Andria to sign the Treaty of Venice with the emperor. To secure the peace, he sanctioned the marriage of his aunt Constance, daughter of Roger II, with Frederick's son Henry, afterwards 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 William might devote himself to foreign conquests.

Unable to revive the African dominion, William directed his attack on Egypt, from which Saladin threatened the Latin kingdom of Jerusalem. In July 1174, 50,000 men were landed before Alexandria, but Saladin's arrival forced the Sicilians to re-embark in disorder. A better prospect opened in the confusion in Byzantine affairs which followed the death of Manuel Comnenus (1180), and William took up the old design and feud against Constantinople. Durazzo was captured (June 11, 1185). Afterwards while the army marched upon Thessalonica, the fleet sailed towards the same target capturing on their way the Ionian islands of Corfu, Cephalonia, Ithaca and Zakynthos. In August Thessalonica surrendered to the joint attack of the Sicilian fleet and army.

The troops then marched upon the capital, but the troops of the emperor Isaac Angelus overthrew the invaders on the banks of the Strymon (September 7, 1185). Thessalonica was at once abandoned and in 1189 William made peace with Isaac, abandoning all the conquests. He was now planning 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, a naval genius equal to George of Antioch, with 60 vessels kept the eastern Mediterranean open for the Franks, and forced the all-victorious Saladin to retire from before Tripoli in the spring of 1188.

In November 1189 William died, leaving no children. Though Orderic Vitalis records a (presumably short-lived) son in 1181: Bohemond, Duke of Apulia. His title of "the Good" is due perhaps less to his character than to the cessation of internal troubles in his reign. The "Voyage" of Ibn Jubair, a traveller in Sicily in 1183-1185, shows William surrounded by Muslim women and eunuchs, speaking and reading Arabic and living like "a Moslem king."

Text from: en.wikipedia.org/wiki/William_II_of_Sicily