Armagnac (ärmänyäkˈ) [key], region and former county, SW France, in Gascony, roughly coextensive with Gers dept. Auch is the chief town. Armagnac is famous for the brandy bearing the same name. The counts of Armagnac originated in the 10th cent. as vassals of the dukes of Gascony. Their power reached its height with Count Bernard VII, who dominated France in the early 15th cent. Margaret of Angoulême, sister of Francis I of France, married the last count of Armagnac, who died without issue. Armagnac eventually passed to her second husband, Henri d'Albret, king of Navarre, whose grandson became King Henry IV. Henry added Armagnac to the royal domain in 1607.