GUGLIELMO II, king of SICILY, called the GOOD. — Born in 1153, died on 18 November 1189. At the age of 13 he succeeded his father G. I, remaining under the regency of his mother Margherita di Navarra until 1161. He played a major role in the disputes between the papacy and the Empire in Italy during the time of Federico Barbarossa, openly demonstrating his support for Pope Alessandro III and contributing in particular to the attainment of the Peace of Venice in 1177, in which the Emperor recognized his title of king.
His alliance was sought by the other great Italian powers, such as Genoa and Venice; Barbarossa himself attempted to win him over to his side. When negotiations for his marriage to the daughter of the Byzantine emperor Manuele Comneno, who had offered her to him, came to nothing, he married the princess Giovanna d’Inghilterra, daughter of Enrico I. He pursued an expansionist policy, aided by successful military expeditions, especially against the Muslims and the Greek Empire: in 1171 he besieged Alessandria, in 1175 he occupied Tunis, in 1180 he concluded a ten-year peace with Abū Ja'qūb Jūsuf, and in 1181–82 he carried out raids in the Balearic Islands. During the disturbances in the Byzantine Empire following the death of Manuele Comneno, he occupied Durazzo and Tessalonica. He took an interest in the Holy Places and participated in the preparations for the Third Crusade, forcing Saladino in 1188, when he was advancing on Tripoli, to withdraw. — Vedi tav. LXXXVIII.