Celtic church. This term, which describes the Christian church as it developed in Wales, Ireland, and Scotland, recognizes that church practice in all three countries had many features in common (similar intellectual training, similar ideas on, for instance, pilgrimage and penance, similar styles of church building and art), but should not disguise the fact that there were very real differences between them. In particular, the concept of the territorial episcopal diocese was based on the administrative divisions of the Roman empire, with which Ireland had no formal link, and consequently, although it had its fair share of bishops, the diocesan system had difficulty in taking root there. Although Christianity was present in Roman Britain by the early 3rd cent. ad, conversion was a slow and complex affair, and by the time of the Roman withdrawal much of Wales and Scotland was still heathen, and the earliest exact date for the presence of Christians in Ireland is a reference in 431 to Palladius, bishop to ‘the Irish who believe in Christ’. While the earliest missionaries may have come from Gaul, Ireland was evangelized largely from Britain, its most famous British missionary being St Patrick, whose activity probably dates to the early and mid-5th cent. The diffusion of the cult of Patrick, and the growth in the status of Armagh, the ecclesiastical centre most closely associated with him, parallels that of St David in south Wales, while the arrival of the Irish saint Colum Cille (Columba) in Iona, in the territory of Dalriada in Scotland, in 563, marked the start of a lengthy period of Irish missionary activity in Britain and the continent. Those monasteries said to have been founded by Colum Cille were held together and administered in the form of a monastic paruchia, and while territorial dioceses were being established in Wales and Scotland, in Ireland ecclesiastical power was held largely by the abbatial, and frequently hereditary, heads of monastic centres, until the great 12th-cent. reform movement saw the establishment of an organized diocesan system along the lines of that operating throughout the Western church.

Sean Duffy

Celtic Church. The Christian Church in parts of Britain before the arrival of St Augustine from Rome in 596–7. Its early history is uncertain, but it was sufficiently organized to send delegates to the Synod of Arles (314). The Celtic Christians resisted the Roman Christianity of Augustine, and although agreement was reached, e.g. over the date of Easter at the Synod of Whitby (664), the conformity to Roman practice was not accepted everywhere. Celtic Christianity is marked by a kind of heroic devotion, with a simplicity of prayer and art. It was strongly ascetical, and emphasized the importance of anamchairdeas, soul-friendship, and of the anamchara, soul-friend, for counsel in the spiritual life. Many prayers (e.g. Loricae, breastplate prayers, as of the one attributed to St Patrick) have survived and are in increasingly common use today.