http://en.wikipedia.org/wiki/Judicael_Berengar

Judicael alias Berengar[1] was Count of Rennes in the mid-to-late 10th century. There are conflicting accounts of his parentage, one popular solution making him son and successor to a count Berenger by a daughter of Gurvand, Duke of Brittany. However, an 11th century collection of Anjevin genealogies shows him to be son of Pascweten, son of Alan I, King of Brittany.

He is first documented as count in 944. He witnessed charters of Alan II, Duke of Brittany, and on the latter's death apparently fell under the control of Wicohen, Archbishop of Dol, later sources reporting the rescue of Judicael and his wife by son Conan. He appears to have been dead by 979, when his son was at the court of Odo I, Count of Blois.