Carcassonne, town, capital of Aude département, Occitanie region, southwestern France, southeast of Toulouse, near the eastward bend of the Aude River, which divides the city into two towns, the Ville Basse and the Cité. The Cité has the finest remains of medieval fortifications in Europe.

On the summit of an isolated hill rearing abruptly on the Aude’s right bank, the site of the Cité was occupied as early as the 5th century  BCE by the Iberians, then by Gallo-Romans. The inner rampart was built in 485 CE, when Euric I was king of the Visigoths. Clovis failed to take it in 508, though Muslim invaders succeeded in 728, as did Pippin III the Short in 752.