The Church in Caledonia
In the early days of Christianity, a wide number of local practices and traditions developed throughout the Christian world. In western Europe, most of these were eventually subsumed back into the Roman Church, but for many centuries the Celtic Church retained a distinctive identity. The Celtic Church, which draws its tradition from the early monks of Ireland, isn't really a separate church - they certainly still consider themselves part of the Roman Church and have never been declared heretical by the pope. But they're notorious for bucking the system, including a famous controversy two centuries ago over variant liturgies and the dating of Easter. (The Celts eventually gave in and switched to the Roman forms.) In the ninth century they still maintain a number of distinctive practices such as clerical marriage, a unique tonsure (Celtic monks shave everything in front of the ears and crown), and the subordination of bishops to the abbots of monasteries.
Both the Picts and Scots were converted to Christianity by the Irish St. Columba, who founded monasteries throughout the land, including the one on the holy island of Iona. The British and the Anglo-Saxons also received Irish missionaries, but were equally influenced by missionaries from the Roman Church of the continent. Thus in ninth-century Caledonia both Celtic and Roman rites exist side-by-side and are often mixed together. The bishop of St. Andrews, who reports to the archbishop of York, is officially the senior bishop of Alban, but many of the priests and abbots of the kingdom look to the monks of Iona for spiritual leadership.
Monasteries in Caledonia follow one of three models. Benedictine monasteries are most common in the Borders, though they are also found in South Alban. In most of Europe Benedictine monasteries are the monasteries, and few foreigners will be familiar with any monastic rules other than those of St. Benedict, which emphasize self-sufficiency and a very practical way of life. Columban monasteries, based on Irish monastic rules as spread by St. Columba and his student St. Columbanus, were once widespread throughout Britain and the Frankish lands, but are now mainly a local phenomenon of Ireland and Alban. The Columban rule is noted for its strict emphasis on austerity and spirituality. They prefer to have as little as possible to do with the temporal world. Finally, a recent import is the philosophy of the Culdees (from Gaelic kelidei, "vassals of God"), followers of an Irish monastic reform movement which practices extreme asceticism, including flagellation, prolonged psalm-singing while standing in cold water, and nights spent in prayer with arms outstretched in the form of a cross. Culdees can be found in their own communities, dwelling alone as hermits, or living as small groups within Columban monasteries. Conservative Columbans are still not sure how to deal with these radical reformers. Benedictines, of course, will have nothing to do with them.
More Information on the Mundane World of A.D. 875: