Emperor Yōmei (用明天皇, Yōmei Tennō, -587) was the thirty-first emperor of Japan, according to the traditional order of succession. He reigned from 585 until his death.
He is called Tachibana no Toyohi no Mikoto (橘豊日尊) in the Nihon shoki. He is also named Prince Ōe (大兄皇子, Ōe no Miko, literally Crown Prince) and Prince Ikebe (池辺皇子, Ikebe no Miko), after the place where he lived.
He acceded to the throne after the death of his half-brother Emperor Bidatsu.
The fourth son of Emperor Kinmei, his mother was Soga no Kitashi-hime, a daughter of Soga no Iname.
In 586, Yōmei took his half-sister princess Hashihoto no Anahobe (穴穂部間人皇女, Hashihito no Anahobe no Himemiko) as empress consort. She bore him four sons, including Prince Shōtoku, who later became crown prince and regent to Empress Suiko.
According to the Nihon shoki, Yōmei additionally has two concubines.
Emperor Yōmei had seven children by three wives:
Bidatsu's powerful ministers, Mononobe no Moriya and Soga no Umako, retained their respective positions during Yōmei's reign. Umako was the son of Iname, and thus a relative of Yōmei.
Because of the brevity of his reign, Emperor Yōmei did not lead any radical changes in policy, but his support for Buddhism created tensions with Shinto conservatives who opposed its introduction.
Mononobe no Moriya, the most influential supporter of Shinto, conspired with the emperor's brother, Prince Anahobe, and after Yōmei's death they unsuccessfully attempted to seize the throne.
Although Yōmei is supposed to have died of illness, this incident and the brevity of his reign have led some to speculate that he was murdered by Moriya and Anahobe.