HILARIUS (HILARY), ST. (c. , bishop of Arles, was born probably in northern Gaul. In early youth he entered the abbey of Lerins, then presided over by his kinsman Honoratus (St. Honore), and succeeded Honoratus in the bishopric of Arles in 429. He held the rank of metropolitan of Vienne and Nar bonne, and attempted to realize the sort of primacy over the church of south Gaul which seemed implied in the vicariate granted to his predecessor Patroclus (417). Hilarius deposed the bishop of Besancon (Chelidonus), for ignoring this primacy, and for claiming a metropolitan dignity for Besancon. An appeal was made to Rome, and Leo I. used it to extinguish the Gallican vicariate (A.D. 444). Hilarius was deprived of his rights as metro politan to consecrate bishops, call synods or exercise ecclesiastical oversight in the province, and the pope secured the edict of Valentinian III., so important in the history of the Gallican church, "ut episcopis Gallicanis omnibusque pro lege esset quid quid apostolicae sedis auctoritas sanxisset." The papal claims were made imperial law, and violation of them subject to legal penalties (Novellae Valeta. iii. tit. 16). Hilarius died in 449, and is commemorated on May 5.