 His twin brother was Tangaroa, the god of the sea.Rongo was the principal deity of Mangaia.In the Mangaian legend of origin, Rongo's sons by his wife Tavake (his daughter by his wife Te-po-tatango), Rangi, Mokoiro, and Akatauira, lifted the island of Mangaia up out of the underworld, becoming the first settlers and the ancestors of the Nga Ariki tribe, with Rangi becoming the first chief.