FOIX, a town of south-western France, in the middle ages capital of the counts of Foix, and now capital of the department of Ariege, 51 m. S. of Toulouse, on the Southern railway from that city to Ax. Pop. (1931), 4,567. It stands at the confluence of the Arget with the Ariege. Foix probably owes its origin to an oratory founded by Charlemagne, which later became an abbey, in which were laid the remains of St. Volusien, archbishop of Tours in the 5th cent. The county of Foix included roughly the eastern part of the modern department of Ariege, i.e., the basin of the Ariege. During the later middle ages it consisted of a number of small lordships subordinate to the counts of Foix, with a share in the government of the district. Protestantism early entered the county, and severe religious struggles ensued. The Oats of the county can be traced back to the i4th century. The old town is dominated by an isolated rock crowned by the castle (12th, 14th and 15th centuries). St. Volusien is a Gothic church (i4th cent.). The town is the seat of a prefecture, a court of assizes and a tribunal of first instance, and has a chamber of commerce. Iron working is carried on.