It is reported that he may have been a Roman nobleman,[1] but he was also identified with Simon the Leper[2] or as one of the seventy-two disciples of Christ, in keeping with attempts to claim an apostolic origin for the see.

[1] He was consecrated a bishop at Rome and around the middle of the 3rd century, Julian was sent to Gaul, along with the priest Thuribe and the deacon Pavace, to preach the Gospel to the tribe of the Cenomani.

Their capital city was Civitas Cenomanorum (Le Mans), which was suffering from a shortage of drinking water.

[3] Julian converted many other citizens and Le Mans' new bishop cared for the poor, the infirm, and the orphans.

[6] Having rested in a shrine at the Benedictine convent of Notre-Dame-du-Pre since the Middle Ages, most of his relics were burnt or scattered by the Huguenots in 1562.