Son of Apollonius, a poor farmer. As a young man he worked as a shepherd to support his family and neighbors who were poorer than himself. Convert, baptized with his father by Bishop Redemptus of Trani, Italy. Magnus succeeded him as bishop of Trani, chosen by popular acclaim of the local laity and clergy. Evangelized in Fondi, Aquino, and Anagni. During the persecutions of Tarquinius, Magnus fled to Rome, Italy, but tried to secretly return to Trani. Found in a cave near Fondi by imperial soldiers. Martyr.
- beheaded near Fabrateria Vetus, Latium (modern Ceccano, Italy)
- buried in Fondi, Italy
- relics translated from Fondi to Veroli, Italy
- relics translated to the cathedral in Anagni, Italy after a wealthy but superstitious Muslim had some horses die when near them in Veroli