Orthodox Saints of the Pre-Schism See of Rome
GUNDELINDIS (GUENDELINDIS), a daughter of the Duke of Alsace, France, and sister of SS. Attala (3rd December) and Eugenia (16th September). St. Gundelindis was raised by her aunt St. Odilia (13th December), whom she succeeded as Abbess of Niedermünster. She reposed circa 750.
GUNTHRAMMUS, a King of Orléans (r. 561–592), and son of King Chlothar I (r. 511–558) and Queen St. Clotilde (3rd June). King St. Gunthrammus was raised as a non-Christian. He divorced his wife, and had the court physician murdered for failing to cure his ex-wife. Later King St. Gunthrammus became a Christian, and his conscience was so full of guilt for his earlier life that he dedicated the rest of his life and fortune to the Church and helping those in need particularly in time of famine and plague. King St. Gunthrammus reposed in 592, and was acclaimed a saint by his subjects shortly thereafter.
ROGATUS, SUCCESSUS, and COMPANIONS, (Date Unknown), a group of eighteen martyrs in one of the early persecutions in North Africa. Beyond their listing in various martyrologies, no record of their lives is extant.
SIXTUS (XYSTUS) III, forty-fourth Pope of Rome from 432 until his repose in 440. St. Sixtus maintained extensive correspondence with St. Augustine of Hippo (28th August), restored several basilicas in Rome, including Saint Peter’s and Saint John Lateran, and defended the Church against the heresies of Nestorianism and Pelagianism.
SPES, an Abbot of the Abbey of St. Eutychius (Abbazia Sant'Eutizio) in Campi, Umbria, Italy. St. Spes was blind for forty years, but fifteen days (or years, sources are fairly divided on this) before his repose circa 513, his eyesight was miraculously restored.
TUTILO, an Irishman who educated at the Abbey of St. Gall in Switzerland, and then received monastic tonsure there. St. Tutilo was a gifted musician and artist. There are ivory tablets attributed to the saint, which form the cover of the Evangelium Longum at St. Gall, and his paintings can be found Konstanz, Metz, Saint Gall, and Mainz. St. Tutilo reposed circa 915.
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.