RIEZ. - Ancient diocese in the department of Basses-Alpes, in France. A Ligurian city, it was later the capital of the Reii, whence the name "Regium," from which the present name derives. It was a colony of Latin right under Augustus. The first known bishop is Prosper, predecessor of St. Maximus (434-60), who was succeeded by Faustus (462-95), formerly abbot of Lérins.
R. was sacked by the Saxons in 572; the inhabitants and the bishop abandoned the city, which still suffered in the Saracen raids from 793 to 875; the bishop Edolo shortly afterward transferred the see to the hill, to the chapel of St. Maximus, where the inhabitants also moved. Among its prelates are remembered the cardinals Pietro Després in 1318 and Guido Bentivoglio. The diocese, a suffragan of Aix, was suppressed in 1790; in 1801 its territory was united to the see of Digne, whose bishop since 1916 also bears the title of R. The bishop Augier (1096-1130) had the Cathedral and the Baptistery rebuilt; the former, Notre-Dame-de-la-Sède, fell into ruin in the 15th century; near the present church some Gothic bays remain. The Baptistery was of the Provençal and Ligurian type, a quadrilateral building on the outside, surmounted by an octagonal tower that collapsed during the Saracen raids. The interior is an octagon measuring 9.25 x 8.40 m with four small apses and a circular ambulatory; eight Roman granite columns from the Var support the dome. The floor was raised at a later date and the bases of the columns are partly interrupted. The Baptistery was abandoned at the end of the 16th century and the inhabitants called it the Pantheon; ceded to the Confraternity of the tailors, it was consecrated to their patron St. Clarus; then it passed to the White Penitents; at present it is reduced to an archaeological museum. On the hill of St. Maximus the chapel, rebuilt in 1857, preserves a Romanesque apse with an ambulatory supported by six Corinthian columns. From the papers of Peiresc it appears that in the floor mosaic of the cathedral of R. there was the image of Constantine on horseback riding over the body of a vanquished foe; the scene was accompanied by the distich: Rex Constantinus, leprosus, virque benignus, est factus sanus, sacro baptismate tactus. That is, the legend was recalled of the Emperor cleansed of leprosy through Baptism (R. Movat, Mosaïque de R. offrant l'image de Constantin, in Bull. de la Soc. des antiquaires de France, 1885, pp. 68-71).