CHÂTEAU-GONTIER, a town of western France, capital of an arrondissement in the department of Mayenne, on the Mayenne, 18 m. S. by E. of Laval by road. Pop. (1906) 6871. Of its churches, that of St Jean, a relic of the castle, dates from the 11th century. Château-Gontier is the seat of a subprefect and has a tribunal of first instance, a communal college for boys and a small museum. It carries on wool- and cotton-spinning, the manufacture of serge, flannel and oil, and is an agricultural market. There are chalybeate springs close to the town. Château-Gontier owes its origin and its name to a castle erected in the first half of the 11th century by Gunther, the steward of Fulk Nerra of Anjou, on the site of a farm belonging to the monks of St Aubin d’Angers. On the extinction of the family, the lordship was assigned by Louis XI. to Philippe de Comines. The town suffered severely during the wars of the League. In 1793 it was occupied by the Vendeans.