Auch (ōsh), town (1990 pop. 24,728), capital of Gers dept., SW France, in Gascony, on the Gers River. It is a farm market and commercial center with a variety of manufactures and an important trade in Armagnac brandy, poultry, wine, and grain. One of the chief towns of Roman Gaul, it was an archiepiscopal see, the capital of Armagnac (10th cent.), and the capital of Gascony (17th cent.). The old part of town, steep and hilly, is topped by a flamboyant-style Gothic cathedral (15th–16th cent.).