William of the Principate

He participated in the Battle of Civitate in the years of his arrival and was received cordially by his half-brother Humphrey, the reigning count of Apulia.

[1] In 1058, he married Maria, the daughter of Guy, Duke of Sorrento and brother of Guaimar IV of Salerno.

He invited his landless youngest brother Roger to join him, promising him half of all he owned, save his wife and children.

He aided Roger against their elder brother Robert Guiscard, who had succeeded Humphrey, and gave him the castle of Scalea, at Catanzaro.

According to some sources, he died in 1080, though others have him living into the twelfth century (to 1104, 1113, or 1117) and participating in the Guiscard's Byzantine campaigns and being present at the Battle of Durazzo, October 1081.