There is archaeological evidence of insular monasticism as early as the mid 5th century, influenced by establishments in Gaul such as the monastery of Martin of Tours at Marmoutier, the abbey established by Honoratus at Lérins; the abbey of Mont-Saint-Michel; and that of Germanus at Auxerre. Many Irish monks studied at Candida Casa near Whithorn in what is now Galloway in Scotland.
Background
By the fifth century, Martin of Tours had established monasteries at Ligugé and Marmoutier; Cassian, the Abbey of St Victor and the women's Abbey of Saint-Sauveur at Marseille; Honoratus at Lérins; and Germanus at Auxerre. The monastic tradition spread from Gaul to the British Isles shortly thereafter. Lérins was famous for training priests, and a number of its monks became bishops. Benedict Biscop, abbot of St Augustine's Abbey in Canterbury, spent two years there. He later founded St Peter's monastery at Monkwearmouth in Northumbria.
As Christianity spread into Ireland and parts of Great Britain during the late 4th and 5th centuries, monastic communities emerged in places such as Iona, Lindisfarne and Kildare. Several early Irish monks were noted for being missionaries, traveling into Great Britain and continental Europe.
History
The Roman, and therefore Saxon conception of ecclesiastical government was territorial and diocesan. The Celtic conception was tribal and monastic. In the British Isles in the 5th century, the earliest monastic communities in Ireland, Wales and Strathclyde followed a different, distinctly Celtic model. It seems clear that the first Celtic monasteries were merely settlements where the Christians lived together – priests and laity, men, women, and children alike – as a kind of religious clan. At a later period actual monasteries both of monks and nuns were formed, and later still the eremitical life came into vogue.
The early Celtic monasteries were like small villages, where the people were taught everything from farming to religion, with the idea in mind that eventually a group would split off, move a few miles away and establish another monastery. In this way, the Celtic way of life, and the Celtic Church propagated its way across Ireland and eventually to Western Britain and Scotland. Irish monks spread Christianity into Cornwall, Wales, and Scotland. St. Ninian established a monastery at Whithorn in Scotland about 400 AD, and he was followed by St. Columba (Iona), and St. Aidan, who founded a monastery at Lindisfarne in Northumbria. Columban wandering monks became missionaries. Founding saints were almost invariably lesser members of local dynasties, and their successors were often chosen from among their kin. Ultan, abbot-bishop of Arbraccan, was a disciple and kinsman of Declán of Ardmore, who made him bishop of Ardbraccan.
The Insular observance, at first so distinctive, gradually lost its special character and fell into line with that of other countries; but, by that time, Celtic monasticism had passed its zenith and its influence had declined.
Scotland
"The impact of monasticism on Scotland was profound and long lasting." Whithorn, an early trading center, precedes the island of Iona by 150 years as a birthplace of Scottish Christianity. The oldest Christian monument in Scotland is "The Latinus Stone", a cemetery stone dated to the mid 5th century. Bede recounts a traditional belief that in 397, Ninian established the first Christian mission north of Hadrian's Wall here.
Ninian
According to the traditional account as expanded in the Vita Sancti Niniani, attributed to Aelred of Rievaulx, Ninian was a Briton who had studied in Rome. On his return, he stopped to visit Martin of Tours, who sent masons with him on his homeward journey. These masons built a church of stone, on the shore. Shortly thereafter (397), upon learning of Saint Martin's death, Ninian dedicated the church to him. Ninian went on to convert the southern Picts to Christianity. There is strong modern scholarly consensus that Ninian and Finnian of Movilla are the same person, whose actual name was "Uinniau".
The small stone church, known as the "Candida Casa" ("shining white house"), was Scotland's first Christian building. Archaeological excavations have suggested that Whithorn was primarily a commercial settlement, whose residents were Christian, and that a more likely location for Ninian's church might have been Kirkmadrine, across the bay. It appears that Rosnat was a double monastery with a separate house for women.