Orthodox Saints of the Pre-Schism See of Rome
CÆDWALLA (CEADWALLA) of WESSEX, a pagan King of Wessex (r. 685–688), who was brought to Christ by St. Wilfrid of York (12th October) who convinced him to repent for his notorious violence, and ruthless treatment of those he conquered. In 688 St. Caedwalla abdicated his throne, and went to Rome. There on Holy Saturday 689 he was baptised by Pope St. Sergius (8th September), and given the name Peter. St. Cædwalla reposed 10 days after his baptism still in Rome and wearing his white baptismal robe, and thus was numbered amongst the Saints. He is buried in a crypt in Saint Peter’s Basilica.
HARDUIN of FONTENELLE, a monk at the Abbey of St. Peter / abbaye Saint-Pierre (later the Abbey of St. Wandrille / abbaye Saint-Wandrille) in Fontenelle, Normandy (north-western France) who spent his later years as a hermit, devoting his time to copying the works of the Fathers. St. Harduin reposed in 811.
HUGH of ANZY-LE-DUC, after finishing his education at the Abbey of St. Savin (abbaye de Saint-Savin-sur-Gartempe), in the present-day town of Saint-Savin-sur-Gartempe, in Poitou, France, St. Hugh received monastic tonsure. He assisted several other monasteries with reviving their monastic life, and later assisted St. Berno of Cluny (13th January) in founding the Abbey of SS. Peter and Paul of Cluny (abbaye Saint-Pierre et Saint-Paul de Cluny — Cluny Abbey) at Cluny in Aquitaine (south-western France). St. Hugh reposed at Anzy-le-Duc, Burgundy (east-central France) circa 930.
MARCELLINUS, VINCENT, and DOMNINUS (DOMNIN), natives of North Africa who travelled to Gaul where they preached in the Dauphiné, in present-day south-eastern France. St. Marcellinus was consecrated first Bishop of Embrun by St. Eusebius of Vercelli (2nd August) circa 354, he reposed in 374. SS. Vincent and Domininus went on to evangelise the area of Digne-les-Bains in the French Alps and are credited with bringing to Christ the bulk of the population in that region. St. Domininus served as the first Bishop of Digne. After St. Domininus reposed in 380 St. Vincent was made the second bishop of that See, serving until his repose in 394.
MARCIAN of AUXERRE, a wonderworking monk at the Abbey of SS. Cosmas and Damian / abbaye de saint Cosme et saint Damien (later the Abbey of St. Marianus / Abbaye Saint-Marien d'Auxerre) in Auxerre in Burgundy (east-central France). There he was given the obedience of keeping the Abbey’s cattle. The date of the repose of St. Marcian is listed as taking place somewhere between 466 and 477.
SULPICIUS and SERVILIAN, martyrs in Rome circa 117 who were beheaded during the reign of the Emperor Trajan (r. 98–117). According to tradition they were converted to the Faith through the prayers of St. Flavia Domitilla (12th May).
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”.
Details of British Saints excerpted from Orthodox Saints of the British Isles.
Details of continental saints from these sources.
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.