town, Puy-de-Dôme département, Auvergne région, south-central France, west of Lyon, created in 1731 by the union of Clermont and Montferrand. It stands on the small Tretaine River. Surrounded by hills to the north, west, and south, the town opens to the east onto the extremity of the Limagne Plain. The houses of the old town of Clermont are mostly built of dark volcanic rock, as is the 13th-century cathedral. The 12th-century church of Notre-Dame-du-Port is a fine example of Auvergnat Romanesque architecture. The Renaissance Maison des Architectes houses the Musée du Ranquet, devoted to the town's past and to Blaise Pascal, who was born in Clermont. A university town, Clermont-Ferrand is also a tourist and commercial crossroads: its influence extends throughout the valley of the Allier and the neighbouring plateaus. A great part of the town's prosperity once rested on the rubber industry, especially the manufacture of rubber tires. Although it has curtailed its local operations, tire and rubber manufacturer Michelin still maintains its headquarters in Clermont-Ferrand and continues to play an important role in the town's economy. Other industries include food processing, pharmaceuticals, electronics, medical products, machinery, and clothing. Many firms produce components for the automotive and aeronautical industries. Much recent economic development has been associated with the service sector, with rapid growth of business services and retailing and continued expansion of higher education and research (in both the public and private sectors). The Polydome exhibition and conference centre (1999) was built to reinforce the role of business tourism in the town. A regional airport lies to the east of Clermont-Ferrand at Aulnat.

Named Augustonemetum by the Romans, Clermont was converted to Christianity in the 3rd or 4th century AD by Saint Austremonius, who became the first bishop of Clermont. Its bishopric gave it great ecclesiastical importance during the Middle Ages, and it was there that Pope Urban II preached the First Crusade in 1095. Far from the central authority in Paris, the local nobility became tyrannical, and Louis XIV sent judges to punish their excesses. The town was hardly affected by the French Revolution and grew into a large manufacturing centre in the 19th century. Pop. (1999) 137,140; (2004 est.) 139,600.