Emperor Bidatsu
Emperor Bidatsu (敏達天皇, Bidatsu-tennō, 538 – 14 September 585) was the 30th emperor of Japan, according to the traditional order of succession.The years of reign of Bidatsu start in 572 and end in 585; however, there are no certain dates for this emperor's life or reign. 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 Yamato dynasty.
Emperor Bidatsu (敏達天皇, Bidatsu-tennō, 538 – 14 September 585) was the 30th emperor of Japan, according to the traditional order of succession.The years of reign of Bidatsu start in 572 and end in 585; however, there are no certain dates for this emperor's life or reign. 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 Yamato dynasty.

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 Nunakura no Futotamashiki (渟中倉太珠敷).
His palace in Yamato Province was called Osada no Miya of Iware.

Events of Bidatsu's life
In the 15th year of Kimmei's reign, Bidatsu was named Crown Prince.In the 32nd year of Kimmei-tennō's reign (欽明天皇32年, 572), the old Emperor died, and the succession was received by his second son. Soon after, Emperor Bidatsu is said to have acceded to the throne.Bidatsu's contemporary title would not have been tennō, as most historians believe this title was not introduced until the reigns of Emperor Tenmu and Empress Jitō. Rather, it was presumably Sumeramikoto or Amenoshita Shiroshimesu Ōkimi (治天下大王), meaning "the great king who rules all under heaven". Alternatively, Bidatsu might have been referred to as ヤマト大王/大君 or the "Great King of Yamato".
Bidatsu's reign was marked by power struggles about Buddhism. 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 Korean Kingdoms and, according to Nihon Shoki, his court successfully established relations with Baekje and Silla, two of the Three Kingdoms of Korea.The Emperor 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. The Emperor is traditionally venerated at a memorial Shinto shrine (misasagi) at Osaka.
The Imperial Household Agency designates this location as Bidatsu's mausoleum. It is formally named Kawachi no Shinaga no naka no o no misasagi.

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: Hirohime (広姫, d.575), Prince Okinaga-no-Mate's daughter
First Son: Prince Oshisako no Hikohito no Ōe (押坂彦人大兄皇子, b.556)
Princess Sakanobori (逆登皇女)
Princess Uji (菟道皇女), Saiō
Empress: Princess Nukatabe (額田部皇女), later Empress Suiko, Emperor Kinmei's daughter
Princess Uji no Kaitako (菟道貝蛸皇女, b.570), married to Prince Shōtoku
Prince Takeda (竹田皇子)
Princess Oharita (小墾田皇, b.572), married to Prince Oshisako-no-Hikohito-no-Ōe
Princess Umori (鸕鶿守皇女)
Prince Kazuraki (葛城王)
Prince Owari (尾張皇子), father of Tachibana-no-Oiratsume (Prince Shōtoku's consort)
Princess Tame (田眼皇女), married to Emperor Jomei
Princess Sakurai no Yumihari (桜井弓張皇女), married to Prince Oshisako-no-Hikohito-no-Ōe, later married to Prince Kume (Emperor Yomei's son)
Consort: Kasuga-no-Ominako-no-Iratsume (春日老女子), Kasuga no Nakakimi no Omi's daughter
Prince Naniwa (難波皇子, 560-587)
Prince Kasuga (春日皇子, 560-615)
Princess Kuwata (桑田皇女)
Third Son: Prince Ohomata (大派皇子, b.585)
Concubine: Unako no Otoshi (菟名子), Ohoka no Obito no Okuma's daughter
Princess Futohime (太姫), also 桜井皇女
Princess Nukatehime (糠手姫皇女, 570-664), married to Prince Oshisako no Hikohito no Ōe

See also
Emperor of Japan
List of emperors of Japan
Imperial cult

Notes
References
Aston, William George. (1896). Nihongi: Chronicles of Japan from the Earliest Times to A.D. 697. London: Kegan Paul, Trench, Trubner.  OCLC 448337491
Brown, Delmer M. and Ichirō Ishida, eds. (1979). Gukanshō: The Future and the Past. Berkeley: University of California Press. ISBN 978-0-520-03460-0;  OCLC 251325323
Hopkins, Donald R. (2002). The Greatest Killer. Chicago: University of Chicago Press. ISBN 9780226351667; ISBN 9780226351681;   OCLC 49305765
Ponsonby-Fane, Richard Arthur Brabazon. (1959). The Imperial House of Japan. Kyoto: Ponsonby Memorial Society. OCLC 194887
Titsingh, Isaac. (1834). Annales des empereurs du Japon (Nihon Ōdai Ichiran). Paris: Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland.  OCLC 5850691
Varley, H. Paul. (1980). Jinnō Shōtōki: A Chronicle of Gods and Sovereigns. New York: Columbia University Press. ISBN 978-0-231-04940-5;  OCLC 59145842