The first church is though to have been built in the 6th century during the reign of Theodoric, regent of the Visigoth kingdom. The church first appears in the official deeds in 925. On Thursday June 12, 1096, Pope Urbain II visited Carcassonne and blessed the stones used to build the cathedral of Saint Nazaire and Saint Celse. The construction was finished in the first half of the 12th century. Only the main and side naves of the Romanesque cathedral remain, which also featured a cloister. Part of the gothic transept and choir was built on the site of the Romanesque choir after 1269, when Louis IX granted the bishop and the chapter the right to encroach upon the public highway by a distance of two "cannes" (an old unit of measurement, representing about 3.5 metres). The gothic changes were finished in the 14th century under the bishoprics of Pierre de Rochefort (1300-1321) and Pierre Rodier (1323-1330). Numerous changes were made to the edifice that lost its cathedral status in 1803 to the Saint Michel church located inside the walled city. In 1898, Pope Leon XIII granted the title of basilica to the church. (Cl. M.H. 1840)

St. Nazarius' Basilica