In his early youth, or the 420s, Hilary joined the
abbey of Lérins which was, at the time, presided over by his kinsman
Honoratus. 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
Augustine of Hippo, 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. The pope also secured the
edict of
Valentinian III, so important in the history of the Gallican church, which freed the Church of Vienne from all dependence on that of Arles. These papal claims were made imperial law, and violation of them were subject to legal penalties. Léon Clugnet suggests that the dispute arose from the fact that the respective rights of the Court of Rome and of the metropolitan were not sufficiently clearly established at that time, and that the right of appeal to the pope was not explicitly enough recognized. Traditionally, he is said to have died on the 5th of May 449 at the age of 48. Following his death, Hilary's name was introduced into the Roman
martyrology. == Writings ==