He was a son born between Ugayafukiaezu and the daughter of Watatsumi (tutelary of the sea), Tamayoribime, and he was the older brother of the first Emperor, Emperor Jimmu.
ウガヤフキアエズ、海神の娘であるタマヨリビメの子で、初代天皇・神武天皇の兄である。