Religion in Iceland
Religion in Iceland has been predominantly Christianity since its adoption as the state religion by the Althing under the influence of Olaf Tryggvason, the king of Norway, in 999/1000 CE. Until then, in the 9th and 10th centuries, the prevailing religion among the early Icelanders — who were mostly Norwegian settlers fleeing Harald Fairhair's monarchical centralisation in 872–930, with some Swedes and Norse British settlers — was the northern Germanic religion, which persisted for centuries even after the official Christianisation of the state. Starting in the 1530s, Iceland, originally Roman Catholic and under the Danish crown, formally switched to Lutheranism with the Icelandic Reformation, which culminated in 1550.