It was the ancient capital of the country of the Vocontii; it became a flourishing Roman residence where they built a theatre, baths, aqueducts, and a bridge still in use. Christianity is attested by its bishops and monuments. It was sacked by the Barbarians, and in the 11th century it was spared thanks to its bishops, who were however opposed in the 12th century by the counts of Toulouse, who erected a castle on the hill situated on the left bank of the Ouvèze around which the feudal town gradually formed in the 14th and 15th centuries, gradually abandoning the right bank where construction resumed only in the 18th century with the convents of the Cordeliers and the Dominicans.
The papal administration of the Comtat Venaissin ensured prosperity for the town until the French Revolution, which also saw the suppression of the diocese. The first bishop seems to have been that Daphnus who attended the Council of Arles in 314 (G. Morin, Un écrit de st Césaire d'Arles renfermant un témoignage sur les fondateurs des églises de Gaule, in Revue bénédictine, 46 [1934], pp. 190-205). Bishop Auspicius appears at the Councils of Riez in 439, of Orange in 440, of V. in 442; he was succeeded by Fonteius in 450, who is mentioned in documents from 451 and 463 (Jaffé-Watt, tenbach, 479, 557) and by Sidonius Apollinaris in 475 (Ep., VI, 7; VII, 4); then Gemellus who was at the Council of Epaone in 517, Alethius who attended the provincial councils of the years 527, 529, 533 and that of Orléans in 541; then Theodasius; Quirinus who was at the Council of Paris in 579; Artemius present at the Councils of Mâcon in 581 and of Vaison in 584; Vincent at that of Paris in 614; Prunius at that of Chalon-sur-Saône in 650; he founded the monastery of Grasellum (Groseau); Bishop Elias appears in 879 among those present at the assembly of Mantille. Among the more recent bishops, mention should be made of Dr. F. M. Suárez (1665-66), d. in Rome on 7 Dec. 1677, notable collector of Christian inscriptions of Rome (cod. Vat. lat. 9136, 9140; Barb. lat. 1804, 2109, 3017, 3084; Chis. I, VI, 205 ff.; cf. A. Silvagni, Inscr. Chr. Urbis Romae, nova series, I, Rome 1922, pp. XLIX-L).
The ancient cathedral of Notre-Dame stands on a pre-existing construction from the 6th or 7th century, formed by a three-aisled building ending in three apses, where excavations carried out by Mons. J. Sautel from 1949-51 have made it possible to recognize that the Christian basilica was erected on the site of a large Roman public building; the main apse and the two side ones rest on remains of a Roman building from the 1st century of which 23 drums of fluted columns remain, fragments of Corinthian capitals and large stone blocks; the triumphal arch is supported by Roman marble columns with square bases and large ancient capitals like the marble blocks of the presbyterial seat and the episcopal chair. Beneath the altar a tomb was found carved into a decorated architrave block; further on, other notable column shafts were found for a total of 30 and fragments of painted plaster, tiles, etc. The basilica, ruined in the 9th-10th centuries, was restored at the beginning of the 11th and rebuilt in the mid-12th century; but interrupted, it was completed in the 13th century and decorated; on the outside of the north aisle an inscription was carved recalling the works; from this aisle one enters the cloister with paired columns, restored in the 19th century. In the cloister, besides notable Christian inscriptions, there is a carved Christian sarcophagus (Wilpert, Sarcofagi, p. 325). The church, dedicated to St. Quirinus, was rebuilt by Mons. G. M. Suárez (1665-66); it has a characteristic apse divided by six columns into a pentagonal shape with two semicircular apsidioles at the beginning; while on the outside it has a triangular shape.
The municipal museum is precious, with imperial statues including a silver bust; but many statues have migrated to the British Museum, to St-Germain, to Avignon, to Marseilles, to Lyons, to Nîmes, to Grenoble, to Valence, etc.