In April 809, the Emperor abdicated and Prince Kamino (Emperor Saga) succeeded to the Imperial Throne, whereupon Emperor Saga appointed Prince Takaoka (Emperor Heizei's son) as the crown prince.
大同4年（809年）4月、病気のため神野親王（嵯峨天皇）に譲位、嵯峨天皇は平城天皇の子の高岳親王を皇太子に立てた。