CESARIUS, St. — Martyr of Terracina in Campania. According to the *Passio*, written between the 5th and 6th centuries by an author who knew nothing of the martyr’s life, C., of African origin, is said to have been a deacon of Terracina and to have suffered martyrdom under Nero together with his companions Julian, Felix, and Eusebius. Of this entire account, only the name of the martyr C., the place, and the day of his martyrdom—November 1—should be accepted; this date was later included not only in martyrologies but also in Roman sacramentaries such as the Gelasian and Gregorian.
In the *Martyrologium Hieronymianum*, C. is also commemorated on April 21; this likely refers to the dedication of the oratory of St. C., erected within the imperial palace on the Palatine, beside which a Greek monastery later arose.