13 December (30 November O.S.):
- CASTULUS AND EUPREPIS, (date unknown), martyrs in Rome.
- CONSTANTIUS, (fifth century), a priest in Rome and opponent of Pelagianism, under whose supporters he suffered greatly.
- TROJAN (TROYEN), a priest in Saintes, where he later succeeded St. Vivian (28th August) as bishop. St. Trojan reposed in A.D. 533.
- TUDWAL (TUGDUAL), a Welsh monk who went to Brittany and then was consecrated Bishop of Tréguier. St. Tudwal reposed circa A.D. 564, and is commemorated at three places in the Lleyn Peninsular in Gwynedd, and his relics are still venerated in Tréguier.
* - Prior to the Schism the Patriarchate of Rome was Orthodox and fully in communion with the Orthodox Church. As Saint John of Shanghai and San Francisco +1966 said "The West was Orthodox for a thousand years, and her venerable Liturgy is far older than any of her heresies."