Career

He is recognized as a saint by the Roman Catholic and Eastern Orthodox Churches, with his feast day celebrated on 5 May. In his early youth, or the 420s, Hilary joined the abbey of Lérins which was, at the time, presided over by his kinsman Honoratus (Saint Honoré). Hilary seems to have been living in Dijon before this, although other authorities believe he came from Belgica, or Provence.

Hilary may have been a relative or "even the son" of the Hilarius who had been prefect of Gaul in 396 and of Rome in 408.

Hilary succeeded his kinsman Honoratus as bishop of Arles in 429. Following the example of Street Augustine, he is said to have organized his cathedral clergy into a "congregation," devoting a great part of their time to social exercises of asceticism.

He held the rank of metropolitan bishop of Vienne and Narbonne, and attempted to exercise the sort of primacy over the church of south Gaul, which seemed implied in the vicariate granted to his predecessor Patroclus of Arles (417). Hilary deposed the bishop of Besançon, Chelidonus, for ignoring this primacy, and for claiming a metropolitan dignity for Besançon.

An appeal was made to Rome, and Pope Leo I used it, in 444, to extinguish the Gallican vicariate headed by Hilary, thus depriving him of his rights to consecrate bishops, call synods, or oversee the church in the province.

These papal claims were made imperial law, and violation of them were subject to legal penalties. Following his death in 449, Hilary"s name was introduced into the Roman martyrology.