was the 30th emperor of Japan, according to the traditional order of succession.
The traditional regnal years of Bidatsu are 572−585, within Asuka period; however, there are no certain dates for this emperor's life or reign. This is the post-Kofun period of the Yamato Kingship.
The names and sequence of the early emperors were not confirmed as "traditional" until the reign of Emperor Kanmu, who was the 50th monarch of the Imperial House.
Traditional narrative
Historians consider details about the life of Emperor Bidatsu to be possibly legendary, but probable. The name Bidatsu-tennō was created for him posthumously by later generations.
In the Nihon Shoki, he is called .
His palace in Yamato Province was called Osada no Miya of Iware.
Bidatsu's contemporary title would not have been titled Tennō, as most historians believe this title was not introduced until the reigns of Emperor Tenmu and Empress Jitō. Rather, it was presumably . Alternatively, Bidatsu might have been referred to as or the "Great King of Yamato".
Bidatsu's reign was marked by power struggles about Buddhism, which had been introduced in his mother's lifetime. The two most important men in the court of Bidatsu were Soga no Umako and Mononobe no Moriya. Soga supported the growth of Buddhism, and Moriya wanted to stop it.
Bidatsu sought to re-establish relations with the Three Kingdoms of Korea, according to Nihon Shoki, his court successfully established relations with two of them, Baekje and Silla.
He died from a disease which afflicted him with sores, apparently the first royal victim of smallpox in Japan.
The actual site of Bidatsu's grave is known.
Genealogy
He was the second son of Emperor Kinmei. His mother, Ishi-hime, was a daughter of Emperor Senka.
Although he had many children, none of them would ever become Emperor. According to Gukanshō, Bidatsu had four empresses and 16 Imperial children (6 sons and 10 daughters).