Prince Sawara (早良親王 Sawara-shinnō) was the 5th son of Prince Shirakabe (later Emperor Kōnin), by Takano no Niigasa. In 781 he was named heir-presumptive after his elder brother succeeded the abdicated Emperor Kōnin as the Emperor Kanmu. In 785, the administrator in charge of the new capital of Nagaoka-kyō, Fujiwara no Tanetsugu, was assassinated. Prince Sawara was implicated because of his opposition to the move of the capital.(along with Otomo no Yakamochi who was executed), exiled to Awaji Province, but starved himself (although a mystery remains) and died on the way there.
He was made a Crown Prince by the Emperor Kanmu after his wife died and his son fell ill (the son allegedly possessed by the spirit of Sawara). Later that year, he was elevated posthumously to become Emperor Sudō (崇道天皇 Sudō-tennō). This is the then only recorded instance of posthumously raising someone to the rank and title of emperor. He was reburied in Yamato.