Background
He was the son of Erard II of Brienne and Agnès of Montfaucon. In 1200 he married Maria, daughter of Tancred of Sicily and sister and heiress of the deposed king William III of Sicily.
He was the son of Erard II of Brienne and Agnès of Montfaucon. In 1200 he married Maria, daughter of Tancred of Sicily and sister and heiress of the deposed king William III of Sicily.
Her precise name is unclear but has been given variously as Mary, Elvira, Albiria, Albinia, or Blanche. She died after 1216. After the Battle of Agnella in 1201, he took the title of King of Sicily. In 1204, he was besieged in the fortress of Terracina by Diepold of Vohburg and lost an eye to an arrow, but he broke the siege and put Diepold to flight.
On June 11, 1205, he was ambushed by a sally of Diepold"s while besieging him at Sarno and mortally wounded.
He died in German hands on June 14, 1205, and was buried at the church of Saint Maria della Foce in Sarno. His widow Elvira married secondly Giacomo Sanseverino, Count of Tricarico, and thirdly Tigrini Guidi, Count of Modigliano (or Count Palatine in Tuscany?).