 Although the first Norse settlers were pagan, Islay has a substantial number of sites of drystone or clay-mortared chapels with small burial grounds from the later Norse era.In the 12th century the island became part of the Diocese of Sodor and the Isles, which was re-established by King Olaf Godredsson.The diocese fell within the jurisdiction of the Archdiocese of Nidaros and there were four principal churches on Islay in the Norwegian "prestegjeld" model