Born in 1153, died on 18 Nov. 1189. At the age of 13 he succeeded his father WILLIAM I, remaining under the regency of his mother Margaret of Navarre until 1161. He played a major part in the disputes between papacy and Empire in Italy at the time of Frederick Barbarossa, openly favouring Pope Alexander III and contributing in particular to the peace of Venice in 1177, where the Emperor acknowledged his title of king.
His alliance was sought by the other great Italian powers, such as Genoa and Venice; even Barbarossa tried to win him over. Negotiations for his marriage to the daughter of the Byzantine emperor Manuel Comnenus, who had offered her, came to nothing; he married instead Princess Joan of England, daughter of Henry I. He pursued an expansionist policy, aided by successful military expeditions especially against the Muslims and the Greek Empire: in 1171 he besieged Alexandria, in 1173 he occupied Tunis, in 1180 he concluded a ten-year peace with Abū Ja'qūb Jūsuf, and in 1181–82 he raided the Balearic Islands. During the disorders in the Byzantine Empire after the death of Manuel Comnenus, he occupied Durazzo and Thessalonica. He took an interest in the Holy Places and took part in preparations for the Third Crusade, forcing Saladin, who was threatening Tripoli, to withdraw in 1188. — See pl. LXXXVIII.