Amator Bishop Auxerre ordained Patrick a priest and the church prospered during his life. After the death of St. Patrick Rome turned against the Celtic Church, because he had organized it according to Coptic teaching. Were in the Liturgy and Baptism because the Egyptians followed the Church of Jerusalem and not Rome. Daily prayers, Mattins, Vespers etc. Monks stay in separate cells.
Baptism is by immersion.
Rome held these practices to be unacceptable Irish customs and strongly attacked the Celtic Church. Rome was worried about the rapid growth of the Celtic Church in Ireland and Britain and its expansion to Europe. The Roman Pope sent Augustine and eighty Benedictine monks to the south of England in order to counter the Celtic movement. By mid 598AD, Augustine had established a base in Canterbury. Thousands from the Celtic Church were rebaptized again- in the Church of Rome.