Emperor Keitai (継体天皇, Keitai Tennō, or more likely Keitai Ōkimi) was the twenty-sixth emperor of Japan, in the traditional order of succession. His reign is placed from 507 to 531, although the dates are not known with certainty.
The tradition, according to whether it is reported by the Kojiki or the Nihon shoki, diverges on his biography. According to the Kojiki, Keitai was born in 485 and died on April 9, 527, and his personal name was Ōdo no Mikoto (袁本杼命).
The Nihon shoki, on the other hand, places his date of birth in 450 and his death on February 7, 531 or 534, and states that he was called Ōdo no Kimi (男大迹王) and Hikofuto no Mikoto (彦太尊).
There is also Wo Ofu Ato-no-Hiko Fudo no Mikoto.
According to the chronicles, he was originally the king of Koshi, a small tribe apparently living in the northern parts of central Japan, perhaps on the coast of the Sea of Japan.
As Japan did not exist at that time, and the entity known as Yamato comprised only a part of the present country, the term emperor is anachronistic to refer to him and some current works of history call Keitai as King Ohoto of Koshi.
According to the chronicles, Keitai was not the son of the previous emperor, but the great-great-great-grandson of Emperor Ōjin, and acceded to the throne when Buretsu died without children or an heir.
Some historians question this genealogy and assume a change of dynasty.
His detailed genealogy is known from the Shaku Nihongi, as a quotation from the Jōgūki (the history of Prince Shōtoku).
There he is described as a son of Ushi no Kimi, a grandson of Ohi no Kimi, a great-grandson of Ohohoto no Kimi (the brother of the empress-consort of Emperor Ingyō) a great-great-grandson of Wakanuke Futamata no Kimi, and a great-great-great-grandson of Emperor Ōjin.
According to the Kojiki and Nihon shoki, his father was Hikonushi no Kimi and his mother Furihime. He was born in the province of Echizen.
When Buretsu dies, Ōtomo no Kanamura and the Mononobe clan recommend Keitai, then 58 years old, as a potential candidate for the Yamato throne, which causes unrest in the province.
Keitai declared his ascension in Kusuba, Kawachi province, and married a younger sister of Buretsu, princess Tashiraga. However, it took him 20 years to enter the province of Yamato, the political center of Japan at that time.
In the last years of Keitai's reign, in 527 or 528, a rebellion led by Iwai broke out in the province of Tsukushi, on the island of Kyūshū. Keitai appointed Mononobe no Arakabi as shogun and sent him to quell the rebellion.
Louis Frederick notes that Keitai was forced to abdicate in favor of his son Ankan and died soon after.
Keitai had 21 children, 9 sons and 12 daughters, from 9 wives. At least two of them were his concubines before his accession to the throne.
The Kojiki mentions firstly Waka-hime (Wakugo-hime), and secondly Menoko no Iratsume. The Nihongi makes Menoko Irohe the first concubine:
Menoko Irohe no Iratsume, daughter of Wohari no Kusaka no Muraji; first concubine; mother of two princes: