Hiallt, a Viking warrior who settled in Normandy, was the ancestor of which Norman noble family, who became rulers of Sicily in eleventh century?

The Hauteville (Italian: Altavilla) was a Norman family originally of seigneurial rank from the Cotentin. The Hautevilles rose to prominence through their part in the Norman conquest of southern Italy. By 1130, one of their members, Roger II, was made the first King of Sicily. His male-line descendants ruled Sicily until 1194. Some Italian Hautevilles took part in the First Crusade and the founding of the Principality of Antioch (1098) ... The traditional account of the family's origin traces them back to Hiallt, a 10th-century Norseman who settled in the Cotentin Peninsula and founded the estate of Hialtus villa, giving rise in corrupted form to the family toponymic Hauteville.