Caius of Milan

Saint Caius (Gaius) was bishop of Milan in the early third century. Orthodox tradition considers him the first bishop of Milan, in the first century, while one Greek source calls him the second. He is venerated as a saint in the Orthodox and the Roman Catholic Church and is commemorated on 27 September.

Almost nothing is known of his life and episcopate, except that he was bishop of Milan in the early third century, that he died on 26 September and that his body was reportedly buried in a cemetery in the area of the basilica Naboriana, now demolished. His relics were later moved to the nearby basilica of Sant'Ambrogio. Medieval texts, such as the Historia Dataria of the eleventh century, add details about his life that are considered legendary, among them his presence in Rome at the martyrdom of Saints Peter and Paul and the conversion by him of Saints Vitalis, Valeria, Gervasius and Protasius.