The history of Christianity in Scotland includes all aspects of the Christianity in the region that is now Scotland from its introduction to the present day. Christianity was probably introduced to what is now southern Scotland during the Roman occupation of Britain. It was mainly spread by missionaries from Ireland from the fifth century and is associated with St Ninian, St Kentigern and St Columba. The Christianity that developed in Ireland and Scotland differed from that led by Rome, particularly over the method of calculating Easter and the form of tonsure until the Celtic church accepted Roman practices in the mid-seventh century. Christianity in Scotland was strongly influenced by monasticism, with abbots being more significant than bishops. In the Norman period, there were a series