Saint Hilary was born roughly around 403 AD and originally came from either Belgica or Provence. He joined the abbey of Lerins in the early 420s and succeeded Honoratus as the Bishop of Arles in 429. Following the example of Saint Augustine, he organized his clergy into a congregation and asked them to dedicate more time to exercising ascetism. During his time as Bishop he became widely known for his great ascetism and piety as well as his eloquence.
Saint Hilary died on May 5th, 449 AD and his feast day is celebrated on the same day.