William Sánchez of Gascony

William II Sánchez (also William Sancho, Basque: Gilen Antso, French: Guillaume Sanche, Gascon: Guilhem Sans, Latin: Willelmus Sancio, Spanish: Guillén or Guillermo Sancho), Duke of Gascony from circa 961 at least until 996, was the younger illegitimate son of duke Sancho IV and successor, around 961, of his childless elder brother, duke Sancho V. He united the County of Bordeaux with the Gascony. Documents of his reign say that his grandfather came from Iberia, lending credence to "phantasmagorical" genealogies placing the origins of García II Sánchez across the Pyrenees. He died in 996 or 997 and was succeeded by his son Bernard William.

Around 970, William was using only the title of count as when "Lord William Sánchez, count of the Gascons" donated land in the village of "Luco Deo" to the monastery of Saint Vincent-de-Lucq. He inherited the county of Bordeaux from his cousin William the Good, son of his aunt Entregodis, who married one Raymond, and united it to Gascony permanently. He later carried the ducal title. Aimoin entitled him "Count of Bordeaux and duke of all Gascony" in his biography of Abbo of Fleury. Before 977, William also added the Agenais and the Bazadais. This expansion of the duchy was probably the cause of an increase in our information about the region and its dukes after a period of obscurity lasting from the Viking raids of the 840s.

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