Seguin I Lupo[1] was Duke of Gascony from 812 until 816,[2] when Louis the Pious deposed him "because of his boundless arrogance and wicked ways", according to the contemporary Frankish chroniclers.
[3] This could imply that the Gascony of Seguin's day was trans-Pyrenean, i.e., comprised lands on both sides of the mountains.
A count of Bordeaux (ruler of the "Burdegalian country", or pagus Burdegalensis) appointed by Charlemagne in 778 had the same name, Seguin, and may have been the same person.
The duke was probably of Gascon (Basque) lineage, though the Vita Hludovici calls him "of the race of Franks" (ex gente Francorum).
Seguin was appointed count in Bordeaux, possibly from a rival family of duke Lupus II.