MORTAGNE, a town of northern France, capital of an arrondissement in the department of Orne, 24 m. E.N.E. of Alençon by rail. Pop. (1906), 3383. A vaulted entrance (15th century), relic of an old stronghold, and the church of Notre-Dame (15th and 16th centuries) with a fine northern portal are of interest. The town is the seat of a sub-prefecture and of a tribunal of first instance, and is a celebrated market for horses of the Perche breed. Mortagne, once capital of the Perche, dates from the 10th century.