Orthodox Saints of the Pre-Schism See of Rome
DOMNIO of BERGAMO, an uncle of St. Eusebia of Bergamo (29th October). Like his niece, St. Domnio was martyred at Bergamo in Lombardy (north-west Italy) by beheading during the Diocletianic Persecution (late third century).
GENEROSUS of POITOU, the Abbot of the Abbey of Saint-Jouin-de-Marnes in Poitou present-day south-western France. St. Generosus reposed circa 682.
HELIER of JERSEY, (Sixth Century), A native of Tongres in present-day Belgium, St. Helier went to Jersey in the Channel Islands where he lived as a hermit. He was martyred by the heathens he was endeavouring to convert to Christianity. St. Helier is the patron saint of Jersey and the capital, St. Helier, takes its name from him.
IRMENGARD, a great-granddaughter of Charlemagne, King of the Franks (r. 768–814), St. Irmengard served the Abbess of the Imperial Abbey of Buchau (Reichsstift Buchau) in Swabia (south-western Germany), and later the Imperial Abbey of Frauenchiemsee in Bavaria (southern Germany). St. Irmengard reposed in 866.
REINELDIS (RAINELDIS, REINALDES), GONDOLF, and GRIMOALD of SAINTES, Martyrs of Saintes, a nun at Saintes in Flanders (present-day Halle Belgium), daughter of St. Amalburga of Mauberge (10th July) and sister of St. Gudula of Brussels (8th January). St. Reineldis was martyred together with SS. Gondolf and Grimoald by the Huns circa 680.
SISENANDUS (SISENANDO) of CÓRDOBA, Martyr of Córdoba, a deacon in Córdoba. In 851, St. Sisenandus was beheaded after being charged with blasphemy during the reign of Emir Abd ar-Rahman II (r. 822–852).
TENENAN of LÉON, (Seventh Century), there is little information on this Saint extant, and that which is available is murky and not all that reliable. It seems he was originally from the British Isles and that he went to Brittany (north-western France), where he lived as an anchorite. At some point St. Tenenan was consecrated Bishop of Léon (south-western France). His relics were enshrined in Plabennec (Brittany).
VALENTINE of TREVES, according to the Roman Martyrology St. Valentine was an early fourth century Bishop of Treves (present-day Trier in Germany’s Rhineland-Palatinate). His absence from lists of prelates of that See have led many contemporary scholars to hypothesise that he is likely to be have been the Valentine who was Bishop of Tongeren and Maastricht (south-west Netherlands). Both are said to have been martyred circa 305, during the Diocletianic Persecution.
VITALIAN of OSIMO, an eighth century Bishop of Osimo in the Italian province of Ancona, who served that See for over three decades. St. Vitalian reposed in 776.
VITALIAN of CAPUA, (Date Unknown), a Bishop of Capua in Campania (southern Italy). No further information on his life is extant.
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.