Castres, a town of south-western France, capital of an arrondissement in the department of Tarn, 29 m. S.S.E. of Albi on a branch line of the Southern railway. Pop. (1906) town, 19,864; commune, 28,272. Castres, the busiest and most populous town of its department, is intersected from north to south by the Agout; the river is fringed by old houses the upper stories of which project over its waters. Wide boulevards traverse the west of the town, which is also rendered attractive by numerous fountains fed by a fine aqueduct hewn in the rock. The church of St Benoît, once a cathedral, and the most important of the churches of Castres, dates only from the 17th and 18th centuries. The hôtel de ville, which contains a museum and the municipal library, occupies the former bishop’s palace, designed by Jules Mansart in the 17th century; the Romanesque tower beside it is the only survival of an old Benedictine abbey. The town possesses some old mansions of which the hôtel de Nayrac, of the Renaissance, is of most interest. Castres has a sub-prefecture, tribunals of first instance and of commerce, a board of trade-arbitrators, a chamber of commerce, a branch of the bank of France and two hospitals. There are also communal colleges for boys and girls, a school of artillery and school of draughtsmanship. The industrial establishments include manufactories of earthenware and porcelain and metal-foundries, and tanning, leather-dressing, turnery, the making of wooden shoes and furniture, the weaving of woollen and other fabrics, dyeing, and the manufacture of machinery, paper and parchment are carried on.
Castres grew up round a Benedictine abbey, which is believed to have been founded in the 7th century. It was a place of considerable importance as early as the 12th century, and ranked as the second town of the Albigenses. During the Albigensian crusade it surrendered of its own accord to Simon de Montfort; and in 1356 it was raised to a countship by King John of France. On the confiscation of the possessions of the D’Armagnac family, to which it had passed, it was bestowed by Louis XI. on Boffilo del Giudice, but the appointment led to so much disagreement that the countship was united to the crown by Francis I. in 1519. In the wars of the latter part of the 16th century the inhabitants sided with the Protestant party, fortified the town, and established an independent republic. They were brought to terms, however, by Louis XIII., and forced to dismantle their fortifications; and the town was made the seat of the chambre de l’édit, or chamber for the investigation of the affairs of the Protestants, afterwards transferred to Castelnaudary (in 1679). The bishopric of Castres, which had been established by Pope John XXII. in 1317, was abolished at the Revolution.