Orthodox Saints of the Pre-Schism See of Rome
CÆREALIS and SALLUSTIA, St. Cærealis a soldier, and his wife St. Sallustia, were catechumens of, and baptised by, Pope St. Cornelius (16th September), with whom they were martyred in 251 during the Decian Persecution (250–251).
CORMAC mac CUILENNÁIN (CORMAC of CASHEL), St. Cormac, a King of Munster (south-western Ireland), was most likely the first Bishop of Cashel in Ireland. Though the reliability of some of the traditions concerning St. Cormac is questionable, he is reputed to have been a great scholar. The authorship of the Sanas Cormaic (Cormac's Glossary), and the now-lost Psalter of Cashel, among other works, have been attributed to him. St. Cormac reposed in 908.
CRESCENTIAN of CARTHAGE, VICTOR of CARTHAGE, ROSULA of CARTHAGE, and GENERALIS of CARTHAGE, said to have been martyred circa 258 in Carthage (a present-day suburb of Tunis, Tunisia) along with St. Cyprian of Carthage (16th September).
CRESCENTIUS of ROME, according to tradition, St. Crescentius was the eleven-year-old son of St. Euthymius of Perugia (29th August). It is said that following the martyrdom of his father, St. Crescentius was brought back to Rome where, even under torture, he proclaimed his faith in Christ, and was subsequently beheaded, during the Diocletianic Persecution (303–313). However, this is all based upon a Life which dates from 1600, and hence, is of questionable veracity.
MATERNUS of COLOGNE, the first known Bishop of Cologne in the present-day German state of North Rhine-Westphalia. He founded a church at the site upon which Cologne Cathedral (Kölner Dom) now stands. St. Maternus reposed circa 325.
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”.
In many cases there are several spelling versions of the names of saints from the British Isles. I use the Oxford Dictionary of National Biography version as the primary version with the more prevalent version in parenthesis e.g. Ceadda (Chad) of Lichfield.