Editing Celtic Christianity (section)

==History==
{{More citations needed section|date=July 2021}}

===Britain===
[[File:St. Aristobulus of Britain.jpg|thumb|upright=0.7|Modern [[icon]] of [[Aristobulus of Britannia]]]]
According to medieval traditions, Christianity arrived in Britain in the [[Christianity in the 1st century|1st century]]. [[Gildas]]'s 6th-century [[De Excidio et Conquestu Britanniae|account]] dated its arrival to the latter part of the reign of the [[Roman emperor]]&nbsp;[[Tiberius]];<ref>[[Gildas]]. ''[[De Excidio et Conquestu Britanniae]]''. 6th century. {{in lang|la}} Translated by [[Thomas Habington]]. ''The Epistle of Gildas the most ancient British Author: who flourished in the yeere of our Lord, 546. And who by his great erudition, sanctitie, and wisdome, acquired the name of ''Sapiens''. Faithfully translated out of the originall Latine'' (8 vols). T. Cotes for William Cooke (London), 1638. Edited and reprinted by [[John Allen Giles]]. [[s:The Ruin of Britain#8|"The Works of Gildas, Surnamed 'Sapiens,' or the Wise", §8]] in ''Six Old English Chronicles of Which Two Are Now First Translated from the Monkish Latin Originals: Ethelwerd's Chronicle, Asser's Life of Alfred, Geoffrey of Monmouth's British History, Gildas, Nennius, and Richard of Cirencester''. Henry G. Bohn (London), 1848. Hosted at [[s:Main Page|Wikisource]].</ref> an account of the [[seventy disciples]] discovered at [[Mount Athos]] in 1854 lists [[Aristobulus of Britannia|Aristobulus]] as "bishop of [[Roman Britain|Britain]]".<ref>{{cite book |author=Pseudo-Hippolytus |author-link=Pseudo-Hippolytus |chapter=On the Seventy Apostles of Christ |title=Ante-Nicean Fathers |volume=5 |pages=254–256 |publisher=Hendrickson Publishers |location=Peabody, MA |date=1999 }}</ref> Medieval accounts of [[Lucius of Britain|King&nbsp;Lucius]], [[Fagan (saint)|Fagan]] and [[Deruvian]], and [[Joseph of Arimathea]], however, are now usually accounted as [[pious fraud]]s.

The earliest certain historical evidence of Christianity among the [[Celtic Britons|Britons]] is found in the writings of such early Christian Fathers as [[Tertullian]] and [[Origen]] in the first years of the [[Christianity in the 3rd century|3rd century]], although the first Christian communities probably were established at least some decades earlier.

[[File:Amphibalus.jpg|thumb|left|''Amphibalus baptizing converts'', from ''The Life of St. Alban'', written and illustrated by [[Matthew Paris]] (†&nbsp;1259)]]
[[File:Line illustration of a Saint's bones unearthed. Wellcome M0007956.jpg|thumb|left|''The discovery of St. Alban's bones'', illustrated in ''The Life of St. Alban'']]

Initially, Christianity was but one of a number of religions: in addition to the native and syncretic local forms of paganism, [[Roman legion]]aries and immigrants introduced other cults such as [[Mithraism]]. At various times, the Christians risked [[Roman persecutions|persecution]], although the earliest known [[Christian martyrs]] in Britain – [[Saint Alban]] and "[[Amphibalus]]" – probably lived in the early 4th century.{{efn|The date of Alban's execution has been a subject of discussion among historians with [[John Morris (historian)|John Morris]] proposing that it took place during the persecutions of Emperor [[Septimius Severus]] as early as 209.<ref>{{citation | url = http://www.roca.org/OA/35/35e.htm | work = Orthodoxy's Western Heritage | title = St. Alban the Martyr | access-date = 21 November 2013 | archive-url = https://web.archive.org/web/20091115145749/http://www.roca.org/OA/35/35e.htm | archive-date = 15 November 2009 | url-status = dead | df = dmy-all }}</ref> The ''[[Anglo-Saxon Chronicle]]'' lists the year 283,<ref>{{cite book |editor1-first=James |editor1-last=Ingram |editor2-first=J.A. |editor2-last=Giles |year=1847 | url = http://www.gutenberg.org/files/657/657.txt | title = Anglo-Saxon Chronicles | publisher = [[Project Gutenberg]] }}</ref> and [[Venerable Bede|Bede]] places it in 305. Still others argue that sometime during the persecutors [[Decius]] or [[Valerian (emperor)|Valerian]] (251–259) is more likely.}} [[Julius and Aaron]], citizens of [[Caerleon]], were said to have been martyred during the [[Diocletianic Persecution]], although there is no textual or archaeological evidence to support the [[folk etymology]] of [[Lichfield]] as deriving from another thousand martyrs during the same years.<ref>{{cite web |url=http://www.british-history.ac.uk/report.aspx?compid=42340|title=Explaining the origin of the 'field of the dead' legend |publisher= British History Online |access-date=20 November 2008}}</ref>

[[Christianization]] intensified with the legalisation of the Christian religion under [[Constantine the Great]] in the early 4th century and its promotion by subsequent Christian emperors. Three [[Romano-British culture|Romano-British]] bishops, including [[metropolitan bishop|Archbishop]]&nbsp;[[Restitutus]] of [[Bishop of London|London]], are known to have been present at the [[Synod of Arles (314)|Synod of Arles in 314]].<ref>{{cite web |url=http://rowanwilliams.archbishopofcanterbury.org/articles.php/1640/1400th-anniversary-of-the-re-organisation-of-the-diocese-of-london |last=Williams |first=Rowan |author-link=Rowan Williams |date=22 May 2004 |title=1400th anniversary of the re-organisation of the Diocese of London |website=Dr Rowan Williams: 104th Archbishop of Canterbury }}</ref> Others attended the [[Council of Serdica]] in 347 and the [[Council of Ariminum]] in 360. A number of references to the church in Roman Britain are also found in the writings of [[Christianity in the 4th century|4th-century]] Christian fathers. Britain was the home of [[Pelagius]], who opposed [[Augustine of Hippo]]'s doctrine of [[original sin]]; [[Germanus of Auxerre|St&nbsp;Germanus]] was said to have visited the island in part to oppose the bishops who advocated [[Pelagianism|his heresy]].

Around 367, the [[Great Conspiracy]] saw the troops along [[Hadrian's Wall]] mutiny, allowing the [[Picts]] to overrun the northern areas of Roman Britain (in some cases joining in), in concert with [[Irish invasions of Wales|Irish]] and [[Anglo-Saxons|Saxon]] attacks on the coast. The Roman provinces seem to have been retaken by [[Theodosius the Elder]] the next year, but many [[Romano-Britons]] had already been killed or taken as slaves. In 407, [[Constantine III (Western Roman Emperor)|Constantine&nbsp;III]] declared himself "emperor of the West" and [[Roman withdrawal from Britain|withdrew his legions]] to [[Gaul]]. The [[Byzantine Empire|Byzantine]] historian [[Zosimus (historian)|Zosimus]] ({{circa|lk=no|500}}) stated that Constantine's neglect of the area's defence against Irish and [[Saxon invasion of Britain|Saxon raids and invasions]] caused the Britons and [[Gauls]] to fully revolt from the [[Roman Empire]], rejecting [[Roman law]] and reverting to [[Celtic law|their native customs]].<ref>{{Cite book|last=Snyder|first=Christopher A.|author-link=Christopher Snyder (historian)|year=1998|title=An Age of Tyrants: Britain and the Britons A.D.&nbsp;400–600|publisher=Pennsylvania State University Press|publication-date=1998|location=University Park|page=22|isbn=0-271-01780-5}}</ref> In any case, Roman authority was greatly weakened following the [[Visigoths]]' [[Sack of Rome (410)|sack of Rome]] in 410. Medieval legend attributed widespread [[Saxon invasions of Britain|Saxon immigration]] to [[Hengist and Horsa|mercenaries]] hired by the British king [[Vortigern]]. The Saxon communities followed [[Anglo-Saxon paganism|a form of Germanic paganism]], driving Christian Britons back to [[Wales]], [[Cornwall]], and [[Brittany]] or subjugating them under kingdoms with no formal church presence.

[[Image:Columba at Bridei's fort.jpg|thumb|upright=0.8|''[[Columba]] at the gate of [[Bridei I]]'s fortress'', book illustration by [[Joseph Ratcliffe Skelton]] (1906)]]

[[Sub-Roman Britain|Fifth and sixth century Britain]], although poorly attested, saw the '''Age of [[list of Welsh saints|Saints]]''' among the Welsh. [[Saint Dubric]], [[Saint Illtud]], and others first completed the [[Christianity in Wales|Christianization of Wales]]. [[Saint Dubricius]] (also known as Dyfrig), who had been bishop at the [[Roman Britain|Roman British]] settlement of [[Ariconium]] (in present-day [[Herefordshire]]) in the mid-fifth century, founded a monastery at nearby [[Hentland]].<ref name="brain">{{cite web |title=The Age of Saints |url=https://www.historic-uk.com/HistoryUK/HistoryofWales/Age-Of-Saints/ |last=Brain |first=Jessica |date=21 January 2022 |publisher=Historic UK |access-date=8 August 2024}}</ref> He ordained [[Samson of Dol]], who went on to evangelize Brittany.<ref>[http://www.newadvent.org/cathen/13422c.htm  Huddleston, Gilbert. "St. Samson." The Catholic Encyclopedia] Vol. 13. New York: Robert Appleton Company, 1912]</ref>

Unwilling or unable to [[mission (Christianity)|missionize]] among the Saxons in England, Briton refugees and missionaries such as [[Saint Patrick]]{{efn|Note, however, that many events of Patrick's hagiographies may have originally intended the earlier [[Palladius (bishop of Ireland)|Saint Palladius]], a Gaul dispatched to Ireland by [[Pope Celestine I]].}} and [[Finnian of Clonard]] were then responsible for the [[Christianity in Ireland|Christianization of Ireland]]<ref>{{harvnb|Baring-Gould|1898|p=41}}</ref> and made up the [[seven founder saints of Brittany|Seven Founder Saints of Brittany]].<ref>{{harvnb|Baring-Gould|1898|p=26}}</ref> The Irish in turn made Christians of the Picts and English. [[Saint Columba]] then began the conversion of the [[Dál Riata#Religion and art|Dál Riata]] and the other peoples of [[History of Christianity in Scotland|Scotland]], although native saints such as [[Saint Mungo|Mungo]] also arose. The history of [[Christianity in Cornwall]] is more obscure, but the native church seems to have been greatly strengthened by Welsh and Irish missionaries such as Saints&nbsp;[[Saint Petroc|Petroc]], [[Saint Piran|Piran]], and [[Saint Breaca|Breaca]]. Extreme weather (as [[extreme weather events of 535–536|around 535]]) and the attendant famines and disease, particularly the arrival of the [[Plague of Justinian]] in Wales around 547 and Ireland around 548, may have contributed to these missionary efforts.<ref>{{harvnb|Hughes|2005|pp=310–311}}</ref>

There is also evidence for the continuation of Christianity in south and east Britain after the [[Anglo-Saxon settlement]], for example with an active [[shrine to Saint Alban]].<ref>Page 72, Essays in Anglo-Saxon History, James Campbell, 1995, Bloomsbury Publishing</ref> There are references in Anglo-Saxon poetry, including ''[[Beowulf]]'', that show some interaction between pagan and Christian practices and values. While there is little scholarly focus on this subject, there is enough evidence from Gildas and elsewhere that it is safe to assume some continuing – perhaps more free – form of Christianity survived. Richard Whinder states "(The Church's pre-Augustine) characteristics place it in continuity with the rest of the Christian Church in Europe at that time and, indeed, in continuity with the Catholic faith&nbsp;... today."<ref>Whinder, R, Christianity in Britain before St Augustine Catholic History Society 2008</ref>

{{anchor|saints}}The title of "[[Christian Saint|saint]]" was used quite broadly by British, Irish, and English Christians. Extreme cases are Irish accounts of [[Gerald of Mayo]]'s presiding over 3,300 saints and Welsh claims that [[Bardsey Island]] held the remains of 20,000.{{efn|The [[Bollandists]] compiling the ''[[Acta Sanctorum]]'' were even driven to complain of the Irish "canonising<!--sic--> dead men in troops whenever they seemed to be somewhat better than usual".<ref>Quoted translated from the Latin in {{harvnb|Baring-Gould|1898|p=39}}</ref>}} More often, the title was given to the founder of any ecclesiastical settlement, which would thenceforth be known as their ''[[llan (placename)|llan]]''. Such communities were organized on tribal models: founding saints were almost invariably lesser members of local dynasties, they were not infrequently married, and their successors were often chosen from among their kin.<ref name=sabi/> In the 6th century, the "[[Welsh Triads|Three Saintly Families of Wales]]" – those of the invading Irish Brychan and [[Hen Ogledd]]'s [[Cunedda Wledig]] and [[Caw of Strathclyde]] – displaced many of the local [[Siluria]]n rulers in favor of their own families and clans.<ref name=sabi>{{harvnb|Baring-Gould|1898|pp=30–40}}</ref> By some estimates,<ref>{{cite web |first=Rowan |last=Williams |url=http://www.walesbooks.com/reviews1.php |title=Reviews and comments on ''The Book of Welsh Saints'' }}</ref> these traditions produced over 800 [[pre-congregational saint]]s that were venerated locally in Wales, but invasions by [[Saxon invasions of Wales|Saxons]], Irishmen, [[Viking invasions of Wales|Vikings]], [[Norman invasion of Wales|Normans]], and others destroyed many ecclesiastical records. Similarly, the distance from Rome, hostility to native practices and cults, and relative unimportance of the local sees has left only two local Welsh saints in the [[General Roman Calendar]]: Saints [[Saint David|David]] and [[Saint Winifred|Winifred]].

Insular Christianity developed distinct traditions and practices, most pointedly concerning the ''[[computus]]'' of [[Easter controversy|Easter]], as it produced the most obvious signs of disunity:<ref name=Lloyd175176>{{harvnb|Lloyd|1912|pp=175–177}}</ref> the old and new methods did not usually agree, causing Christians following one system to begin celebrating the feast of the [[Resurrection of Jesus|Resurrection]] while others continued to solemnly observe [[Lent]].{{efn|Indeed, this is noted as occurring in the household of King [[Oswiu of Northumbria]], whose kingdom had been evangelised by both Irish and Roman missionaries.<ref>{{harvnb|Lloyd|1912|p=176}} and note.</ref>}} [[Christian monasticism|Monasticism]] spread widely; the [[Llandaff Charters]] record over fifty religious foundations in southeast Wales alone. Although the ''[[clasau]]'' were rather modest affairs, great [[monasteries]] and [[monastic schools]] also developed at [[Llantwit Major]] (''{{lang|cy|Llanilltud Fawr}}''), [[Bangor Cathedral#History|Bangor]], and [[Iona#History|Iona]]. The [[tonsure]] differed from that elsewhere and also became a point of contention. A distinction that became increasingly important was the nature of church organisation: some monasteries were led by married clergy, inheritance of religious offices was common (in Wales, as late as the 12th century),<ref name=powys>{{cite web |url=http://history.powys.org.uk/history/common/early1.html |title=Early Christianity in Wales |website=Powys Digital History Project }}</ref> and illegitimacy was treated much more leniently with fathers simply needing to acknowledge the child for him to inherit an equal share with his brothers. Prior to their conquest by England, most churches have records of bishops and priests but not an established [[parish]] system. Pre-conquest, most Christians would not attend regular services but relied on members of the monastic communities who would occasionally make preaching tours through the area.<ref name=powys/>

====Wales====
{{see also|List of Welsh saints}}
[[File:LeningradBedeHiRes.jpg|thumb|upright=0.8|A portrait of [[Augustine of Canterbury]] from an 8th-century manuscript of [[Bede]]'s ''[[Historia ecclesiastica gentis Anglorum]]'']]

Christianity had entered Wales during [[Roman Britain|Roman]] times, initially as an urban religion. At first it was banned by the authorities who were suspicious of its secrecy. The first Christian martyrs, in the fourth century in Wales were executed at the legionnaires' town of [[Caerleon]] (near present-day [[Newport, Wales|Newport]] in South Wales).<ref name="bbc">{{cite web |title=The age of the saints |url=https://www.bbc.co.uk/wales/history/sites/themes/religion/religion_age_of_saints.shtml |publisher=BBC |year=2014 |access-date=8 August 2024}}</ref>

[[Bardsey Island]] has been an important religious site since the 6th century, when [[Saint Cadfan]] founded a monastery there.<ref>{{cite book|url=https://books.google.com/books?id=-G4AAAAAMAAJ&pg=PA9|last=Baring-Gould|first=Sabine|title=The Lives of the British Saints: The Saints of Wales and Cornwall and Such Irish Saints as Have Dedications in Britain|publisher=C. J. Clark|date=1908|page=9|volume=2}}</ref> In medieval times it was a major centre of pilgrimage.<ref>{{cite web|url=https://britishheritage.com/celtic-saints-wales|last=Ellis|first=Sian|title=Into the age of Celtic saints in Wales|website=British Heritage Travel|date=16 August 2024}}</ref>

The saints seem often to have emerged from native tribal traditions.  They were frequently from community nobility, but inspired by the [[Desert Fathers]], they renounced the privileges of such positions to live remote, secluded, monastic lives.<ref>{{cite web |title=Peaceful places of inspiration along the River Wye |url=https://www.wyevalley-nl.org.uk/wp-content/uploads/Celtic-Churches-Leaflet.pdf |publisher=Wye Valley AONB Partnership |access-date=9 August 2024}}</ref> Their identity would emerge separately from the base established in England by [[Saint Augustine]] in 597&nbsp;AD.<ref name="brain" /> Although little else is known about these people, their influence persists in place names all over Wales, pre-fixed by the word Llan: an old Welsh word referring to land consecrated for burials and churches.<ref name="bbc" />

At the end of the 6th century, [[Pope Gregory I]] dispatched a [[Gregorian mission|mission]] under [[Augustine of Canterbury]] to convert the [[Anglo-Saxons]], establish new sees and churches throughout their territories, and reassert papal authority over the native church. Gregory intended for Augustine to become the metropolitan bishop over all of southern Britain, including the existing dioceses under Welsh and Cornish control. Augustine met with British bishops in a series of conferences – known as the [[Synod of Chester]] – that attempted to assert his authority and to compel them to abandon aspects of their service that had fallen out of line with Roman practice. The [[Northumbria]]n cleric [[Bede]]'s ''[[Ecclesiastical History of the English People]]'' is the only surviving account of these meetings: according to it, some of the clerics of the nearest British province met Augustine at a site that was known thereafter as Augustine's Oak. Augustine focused on seeking assistance for his work among the Saxons and reforming the Britons' obsolete method for calculating Easter; the clerics responded that they would need to confer with their people and await a larger assembly.<ref name=Lloyd174175>{{harvnb|Lloyd|1912|pp=174–175}}</ref> Bede relates that the bishops particularly consulted a hermit on how to respond. He told them to respond based on Augustine's conduct: were he to rise to greet them, they would know him for a humble servant of Christ and should submit to his authority but, were he to remain seated, they would know him to be arrogant and prideful and should reject him. As it happened, Augustine did keep his seat, provoking mistrust. In the negotiations that followed, he offered to allow the Britons to maintain all their native customs but three: they should adopt Rome's more advanced method of calculating the date of Easter, reform their baptismal ritual, and join the missionary efforts among the Saxons. The British clerics rejected all of these, as well as Augustine's authority over them.<ref name=Lloyd174175/> [[John Edward Lloyd]] argues that the primary reason for the British bishops' rejection of Augustine – and especially his call for them to join his missionary effort – was his claim to sovereignty over them, given that his see would be so deeply entwined with the Anglo-Saxon [[Kingdom of Kent]].<ref name=Lloyd177>{{harvnb|Lloyd|1912|p=177}}</ref>

The death of hundreds of British clerics to the pagan king [[Æthelfrith]] of the [[Kingdom of Northumbria]] around 616 at the [[Battle of Chester]] was taken by Bede as fulfillment of the prophecy made by Augustine of Canterbury following the Synod of Chester.<ref>{{harvnb|Bede|1999|pp=106}}</ref> The prophecy stated that the British church would receive war and death from the Saxons if they refused to proselytise.<ref>{{harvnb|Lloyd|1912|p=180}}</ref><ref>{{harvnb|Yorke|2006|pp=118–119}}</ref><ref>{{Cite wikisource|title =Ecclesiastical History of the English Nation. Book 1 Chapter XXII|author=Bede|authorlink=Bede|year= 1910|wslink =Ecclesiastical History of the English Nation (Jane)/Book 1#32|publisher=J.M. Dent; E.P. Dutton|location=London}}</ref>{{efn|Bede says 1,200 British clergy died; the ''[[Anglo-Saxon Chronicle]]'' says 200. Bede is unclear on the date of the battle, but the current view is that it occurred in 616.}} Despite the inaccuracies of their system, the Britons did not adopt the Roman and Saxon {{langx|la|computus|label=none}} until induced to do so around 768 by "[[Bishop of Bangor|Archbishop]]" [[Elfodd]] of "Gwynedd". The Norman invasion of Wales finally brought Welsh dioceses under [[Kingdom of England|England]]'s control. The development of legends about the mission of Fagan and Deruvian and [[Philip the Apostle]]'s dispatch of Joseph of Arimathea in part aimed to preserve the priority and authority of the native establishments at [[Diocese of St David's|St David's]], [[Diocese of Llandaff|Llandaff]], and [[Glastonbury Abbey|Glastonbury]]. It was not until the death of [[Bishop of St Davids|Bishop]] [[Bernard (bishop of St Davids)|Bernard]] ({{circa|lk=no|1147}}) that St&nbsp;Davids finally abandoned its claims to metropolitan status and submitted to the [[Province of Canterbury]], by which point the popularity of [[Geoffrey of Monmouth]]'s pseudohistorical ''[[Historia Regum Britanniae]]'' had begun spreading these inventions further afield. Such ideas were used by mediaeval anti-Roman movements such as the [[Lollardy|Lollards]] and followers of [[John Wycliffe]],<ref>{{cite book |last=Tuchman |first=B. |date=1978 |title=A Distant Mirror |publisher=Ballantine Books |location=New York |isbn=0-345-34957-1 }}</ref> as well as by English Catholics during the [[English Reformation]]. The legend that Jesus himself visited Britain is referred to in [[William Blake]]'s 1804 poem "[[And did those feet in ancient time]]".  The words of Blake's poem were set to music in 1916 by [[Hubert Parry]] as the well-known song "Jerusalem".

====Scotland====
{{see also|Hiberno-Scottish mission}}
[[File:Ninian of Whithorn.jpg|thumb|[[Saint Ninian]] as intercessor from ''Book of Hours of the Virgin and Saint Ninian'' (15th century)]]

According to Bede, [[Saint Ninian]] was born about 360 in what is present day Galloway, the son of a chief of the Novantae, apparently a Christian. He studied under [[Martin of Tours]] before returning to his own land about 397. He established himself at [[Whithorn]] where he built a church of stone, "Candida Casa". Tradition holds that Ninian established an episcopal see at the Candida Casa in Whithorn, and named the see for Saint Martin of Tours. He converted the southern Picts to Christianity,<ref>{{cite web |url=http://www.whithorn.com/saint-ninian.htm |title=Saint Ninian |website=The Whithorn Trust |url-status=dead |archive-url=https://web.archive.org/web/20110718042945/http://www.whithorn.com/saint-ninian.htm |archive-date=18 July 2011  }}</ref> and died around 432. Many Irish saints trained at the "Candida Casa", such as [[Tigernach of Clones]], [[Ciarán of Clonmacnoise]], and [[Finnian of Movilla]]. Ninian's work was carried on by Palladius, who left Ireland to work among the Picts. The mission to the southern Picts apparently met with some setbacks, as Patrick charged Coroticus and the "apostate Picts" with conducting raids on the Irish coast and seizing Christians as slaves. [[Ternan]] and [[Saint Serf]] followed Palladius. Serf was the teacher of Saint Mungo,<ref>{{cite web |url=http://www.bartleby.com/210/7/061.html |title=Butler, Alban. "The Lives of the Saints", Vol. VII, 1866 |website=Bartleby |date=12 January 2023 }}</ref> the apostle of Strathclyde, and patron saint of Glasgow.

====Cornwall and West Devon====
{{see also|List of Cornish saints}}
A Welshman of noble birth, Saint Petroc was educated in Ireland. He set out in a small boat with a few followers. In a type of ''peregrinatio'', they let God determine their course. The winds and tides brought them to the Padstow estuary.<ref>{{cite web |url=http://www.padstowparishchurch.org.uk/padstowchurch.htm |title=The Story of St. Petroc |website=St. Petroc's, Padstow |archive-url=https://web.archive.org/web/20130820051815/http://www.padstowparishchurch.org.uk/padstowchurch.htm |archive-date=20 August 2013 }}</ref> [[Kevin of Glendalough]] was a student of Petroc. [[Saint Endelienta]] was the daughter of the Welsh king [[Brychan]]. She also travelled to Cornwall – that is ancient [[Dumnonia]] – to evangelize the locals as did [[St Nonna]] mother of [[St David]] who travelled on to Brittany. Her brother [[Nectan of Hartland]] worked in Devon. Saint Piran is the patron saint of tin miners. An Irishman, [[Ciaran]], he is said to have 'floated' across to Cornwall after being thrown into the sea tied to a millstone. He has been identified on occasion with [[Ciarán of Saigir]].<ref name=schaff>{{cite encyclopedia |url=http://www.ccel.org/ccel/schaff/encyc03/Page_117.html |title=Saint Ciaran of Saigir |encyclopedia=New Schaff-Herzog Encyclopedia of Religious Knowledge |page=117 }}</ref>

===Ireland===
[[File:Stpatrick hilloftara.jpg|thumb|right|St. Patrick]]
{{see also|List of Irish saints}}
By the early fifth century, the religion had spread to Ireland, which had never been part of the Roman Empire. There were Christians in Ireland before [[Palladius (bishop of Ireland)|Palladius]] arrived in 431 as the first missionary bishop sent by Rome. His mission does not seem to have been entirely successful. The subsequent mission of Saint Patrick, traditionally starting in 432,<ref>
{{cite book
 |last1                = Bury
 |first1               = J. B.
 |author-link1         = J. B. Bury
 |orig-date            = 1905
 |title                = Life of St. Patrick and His Place in History
 |url                  = https://books.google.com/books?id=Ow_tOVnda_8C
 |series               = Cosimo classics biography
 |date = December 2008
 |location             = New York
 |publisher            = Cosimo, Inc.
 |publication-date     = 2008
 |page                 = 331
 |isbn                 = 9781605204024
 |access-date          = 5 July 2022
 |quote                = [...] the year of [Patrick's] coming to Ireland, which rests upon clear and unvarying tradition, A.D. 432 [...].
}} 
</ref>
established churches in conjunction with ''civitates'' like his own in [[Armagh]]; small enclosures in which groups of Christians, often of both sexes and including the married, lived together, served in various roles and ministered to the local population.<ref>{{harvnb|Hughes|2005|pp=306 & 310}}</ref><ref>Riley, 82–93, 95–96</ref>{{full citation needed|date=May 2017}} Patrick set up diocesan structures with a hierarchy of bishops, priests, and deacons. During the late 5th and 6th centuries true monasteries became the most important centres: in Patrick's own see of Armagh the change seems to have happened before the end of the 5th century, thereafter the bishop was the abbot also.<ref>{{harvnb|Ryan|1931|pp=100–102}}</ref> Within a few generations of the arrival of the first missionaries the monastic and clerical class of the isle had become fully integrated with the culture of Latin letters.  Besides Latin, Irish ecclesiastics developed a written form of [[Old Irish language|Old Irish]]. Others who influenced the development of Christianity in Ireland include [[Saint Brigid|Brigid]] ({{circa}} 451 – 525), Saint [[Moluag]] ({{circa}} 510 – 592, who evangelised in the area of present-day Scotland) and Saint [[Caillín]] (fl. {{circa | 570}}).