Thurstain Vicomté d’Avranches
- Born: Abt 975, Normandy
- Marriage: Unknown
- Died: After 1041, Normandy
Another name for Thurstain was Thurstain le Goz Vicomté d' Avranches.
According to the Dictionary of National Biography, in the article on Hugh of Avaranches, Earl of Chester, Thurstan (Toustein) was unfaithful to Duke William [of Normandy] in 1040 and helped Henry, King of France in his invasion of Normandy. His son Richard remained loyal and made his father's peace with the duke.
~An Analysis of the Domesday Book of the County of Norfolk, "Predigree of Hugh Lupus," pg. 16
Noted events in his life were:
• Background Information. 725
This ancestry is said to descend from Rongwald or Raungwaldar, Earl of Maere, or the Fair haired, who was the father of Hrolf, or Rollo, the first Duke of Nomandy. Rongwald, like the majority of his countrymen and kinsmen, had several children by a favorite slave, whom he married "more Dancico," and Hrolf Thurstain, the son of one of them, followed his uncle Rollo into Normandy and was able marry Gerlotte de Blois, daughter of Thibaut, Count of Blois and Chartres. From them descended the Lord of Briquebec, Bec-Cripin, Montfort-sur-Risle and others who figure as campanions of the Conqueror.
The third son of Gerlotte was Ansfrid the Dane, the first Vicomte of Hiemois, and father of Ansfrid the second, surnamed Goz, whose son Thurstain Goz was the great favorite of Robert Duke of Normandy, the father of the Conqueror, and accompanied him to the Holy Land. He was intrusted to bring back the relics the Duke had obtained from the Patriarch of Jerusalem to present to the Abbey of Cerisi, in 1035. Thurstain revolted against the Young Duke William in 1041, and was exiled with all his land confiscated and was givem by the Duke to his own mother, Herleve, who was also the wife of Herluin de Contevill.
~The Conquerors and his Companions, pg. 18