Question: Who is William I, Count Of Boulogne's mother?
Sentence (from "Stephen, King of England"): When Henry died in 1135, Stephen quickly crossed the English Channel and with the help of his brother Henry, Bishop of Winchester and Abbot of Glastonbury, took the throne, arguing that the preservation of order across the kingdom took priority over his earlier oaths to support the claim of Henry I's daughter, the Empress Matilda.
Relevant evidence: No