Auxerre (ōsĕrˈ) [key], town (1990 pop. 40,597), capital of Yonne dept., N central France, in Burgundy, on the Yonne River. A commercial and industrial center, it has a great variety of manufactures and an important trade in Chablis wines. Auxerre gave its name to the medieval county of Auxerrois. It became part of Burgundy with the Treaty of Arras (1435). St. Germanus of Auxerre was bishop there in the 5th cent. The former abbatial church of St. Germain (13th cent.) is built on crypts dating back to the 6th cent. The abbey (now a hospital) has a fine Romanesque clock tower. The cathedral (13th–16th cent.) is in the Gothic flamboyant style.