His father was Takechi no Miko, a prince of Emperor Tenmu, and his mother was Minabe no himemiko, a princess of Emperor Tenchi (older maternal half-sister of Empress Genmei) and he was a Koshin (Emperor's family) very close to the main branch.
父は天武天皇の皇子の高市皇子、母は天智天皇の皇女の御名部皇女（元明天皇の同母姉）であり、皇親として嫡流に非常に近い存在であった。