Io is a godly figure whose existence before European (specifically Christian European) arrival has been debated. He didn't appear in manuscripts or oral discourse until late in the 19th century. At least two references to him from 1891 appear in Edward Tregear's "The Maori-Polynesian comparative dictionary", where he is described as "God, the Supreme Being", and as a figure in Moriori genealogy, but as Tiki's descendant. A third reference might be found in the same book under Ngāti Maniapoto's genealogy. It should also be noted that Io seems to be present in mythologies from Hawai‘i, the Society Islands, and the Cook Islands.