William I of Gascony

William I (French: Guillaume, Gascon: Guilhem, Spanish: Guillermo) was the Duke of Gascony, appointed in 846 following the death of Seguin II in battle with the Norse assaulting Bordeaux and Saintes. He battled with the Vikings, and died while trying to retake Bordeaux from them in 848. He was the last Frankish-appointed duke. After his death, the Basque chief Sancho Sánchez probably took control of Bordeaux and was soon recognised as duke.