Orthodox Saints of the Pre-Schism See of Rome
CARON, aside from the fact that he is the patron saint of Tregaron in Dyfed Wales, there is nothing known about this saint.
CARTHAGE the ELDER, St. Carthage the Elder succeeded of St. Kieran (vide infra) as Bishop of Ossory in Ireland. He is mainly known as the tutor and foster-father of his namesake, St. Carthage the Younger (14th May). Beyond that, there is no reliable Life of this saint, but he is said by many to have been a son or grandson of Óengus mac Nad Froích, the first Christian King of Munster (r. 453—489). He is generally believed to have reposed circa 540.
CLEMENT, an Abbot of Santa Lucia Abbey in Syracuse, Sicily, who reposed circa 800.
COLMAN of ARMAGH, (Fifth Century), a disciple of St. Patrick (17th March) St. Colman of Armagh was renowned for his extreme asceticism. He predeceased his holy master, who buried him at Armagh.
EUSEBIUS and COMPANIONS, (Date Unknown), a group of ten martyrs believed to have suffered for the faith in North Africa. However, no further details are extant.
EUSEBIUS, a native of Cremona, who, having heard St. Jerome (30th September) speak, joined his pilgrimage to the Holy Land along with SS. Paula (26th January) and Eustochium (28th September), settling in Bethlehem. St. Eusebius built a hostel for poor pilgrims with the proceeds of the sale of his property in Cremona, and donations he received in Dalmatia and Italy. Later he served as an abbot in Bethlehem. St. Eusebius reposed circa 423.
KIERAN (KIEMAN, KYRAN, CIARAN), “The First-Born of the Saints of Ireland”, St. Kieran was born in Ossory to a noble family. He was most likely consecrated first Bishop of Ossory by St. Patrick (17th March), though there are those who say he was consecrated by the Pope of the time. Regarded as one of the 'Twelve Apostles of Ireland', he was associated with St. Patrick’s work in that land, and was also the founder of a monastery at Saighir. Some claim that he crossed over to Cornwall, and was the same saint as St. Piran (vide infra) who is venerated there as a local saint, though this is highly unlikely. St. Kieran reposed circa 530 at what would have been a very advanced age.
OLIVA, said to have been martyred in 138 in persecutions during the reign of the Emperor Hadrian (r. 117—138). St. Oliva’s relics are enshrined at the church of Sant'Afra in Brescia, Italy.
PIRAN (PYRAN), St. Piran was a hermit near Padstow in Cornwall. Like many of his contemporaries, there are many legends but little reliable facts about his life. Often stories of his life have been entangled with that of St. Kieran of Ossory (vide supra), and there are some who have argued that he is the same saint as St. Kieran of Clonmacnoise (9th September). St. Piran reposed circa 480, and is venerated as the patron saint of miners, also the town of Perranporth on the north coast of Cornwall, England is named after him.
VIRGILIUS of ARLES, St. Virgilius received monastic tonsure at Abbey of Our Lady of Lérins (abbaye Notre-Dame de Lérins), later serving as its Abbot. St. Gregory of Tours (17th November), wrote that St. Virgilius was the first Abbot of the Monastery of St. Symphorien at Autun. Then with the support of his Bishop was consecrated the twentieth Archbishop of Arles. Pope St. Gregory the Dialogist (3rd September) appointed him Papal Vicar in Gaul, and he is widely believed to have consecrated St. Augustine (27th May), Archbishop of Canterbury. St. Virgilius reposed circa 610.
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.