Bidatsu

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).

Bidatsu's first empress, Hirohime, died in the fifth year of his reign. To replace her, he elevated one of his consorts, Princess Nukatabe, to the rank of empress. Nukatabe was his half-sister by their father Kinmei. Later she ascended to the throne in her own right and is today known as Empress Suiko.

He was succeeded first by one of his brothers, Emperor Yōmei, then by another, Emperor Sushun, and then Empress Suiko, his sister and wife, before his grandson, Emperor Jomei, eventually took the throne.

Empress: , Prince Okinaga-no-Mate's daughter First Son:

, Saiō Empress: , later Empress Suiko, Emperor Kinmei's daughter , married to Prince Shōtoku

, married to Prince Oshisako-no-Hikohito-no-Ōe

, father of Tachibana-no-Oiratsume (Prince Shōtoku's consort) , married to Emperor Jomei , married to Prince Oshisako-no-Hikohito-no-Ōe, later married to Prince Kume (Emperor Yomei's son) Consort: , Kasuga no Nakakimi no Omi's daughter

Third Son: Concubine: , Ohoka no Obito no Okuma's daughter , also , married to Prince Oshisako no Hikohito no Ōe