An accepted legend states that the first bishop of Auxerre, St Peregrine, was consecrated by Pope Sixtus II and was sent from Rome at the request of the Christians resident in that part of Gaul. Landing at Marseilles, he preached the gospel in that city, as well as in Lyons on his way. During his episcopate the greater part of the inhabitants of Auxerre are said to have been converted to Christianity. He built a church on the banks of the Yonne and evangelized all the surrounding country. In the mountainous district of the Puisaye, some ten leagues or more south-west of Auxerre, stood the town of Intaranum–the present Entrains–at a point where several roads met. The Roman prefect had a palace there and the place had become a great centre for the worship of Roman deities. On the occasion of the dedication of a new temple to Jupiter, St Peregrine went to the town and appealed to the populace to abandon idolatry. He was seized, brought before the governor and condemned to death. After being cruelly tortured he was beheaded.

This account is based upon two texts, one of which is printed in the Acta Sanctorum May, vol. iii, while the other may most conveniently be consulted in Migne, PL., vol.138, cc.219-221. There is no reason to doubt the fact of the martyrdom, for the Hieronymianum commemorates it on this day and informs us that it took place at the "vicus Baiacus " (Bouhy), where Peregrine was buried. See also Duchesne, Fastes Épiscopaux, vol . ii, p. 431.