 Later missionaries from Ireland were a major source of missionary work in Scotland, Anglo-Saxon parts of Britain, and central Europe (see Hiberno-Scottish mission).Celtic Christianity, the forms of Christianity that took hold in Britain and Ireland at this time, had for some centuries only limited and intermittent contact with Rome and continental Christianity, as well as some contacts with Coptic Christianity.Some elements of Celtic Christianity developed, or retained, features that made them distinct from the rest of Western Christianity, most famously their conservative method of calculating the date of Easter.