Orthodox Saints of the Pre-Schism See of Rome
ADA, (Late Seventh Century), a niece of Engebert, Bishop of Le Mans, St. Ada received monastic tonsure at Soissons and later served as Abbess of the Abbey of Saint Julien du Pré in Le Mans.
BERTOARA, Abbess of Notre-Dame-de-Sales in Bourges from 612 until her repose in 614.
FELIX of BOLOGNA, a disciple of, and deacon under, St. Ambrose in Milan (7th December). St. Felix then served as the fifth Bishop of Bologna. He reposed in 429.
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.