|Emperor of Japan|
|Reign||158 BC – 98 BC (traditional)|
|Died||98 BC (aged 110)|
Kasuga no Izakawa no saka no e no misasagi (春日率川坂上陵) (Nara)
|House||Imperial House of Japan|
Emperor Kaika[a] (開化天皇 Kaika-tennō), also known as Wakayamato Nekohiko Ōbibi no Mikoto (若倭根子日子大毘毘命) in the Kojiki, and Wakayamato Nekohiko Ōbibi no Sumeramikoto (稚日本根子彦大日日天皇) in the Nihon Shoki is the ninth Emperor of Japan, according to the traditional order of succession. Very little is known about this Emperor due to a lack of material available for further verification and study. Kaika is known as a "legendary emperor" among historians as his actual existence is disputed. Nothing exists in the Kojiki other than his name and genealogy. Kaika's reign allegedly began in 158 BC, he had one wife and three consorts of which he fathered five children with. After his death in 98 BC, one of his sons supposedly became the next emperor.
In the Kojiki and Nihon Shoki, only Kaika's name and genealogy were recorded. The Japanese have traditionally accepted this sovereign's historical existence, and an Imperial misasagi or tomb for Kaika is currently maintained; however, no extant contemporary records have been discovered that confirm a view that this historical figure actually reigned. Kaika was born sometime in 208 BC, and is recorded as being the second son of Emperor Kōgen. His empress mother was named Utsushikome, who was the daughter of Oyakuchisukune. Before he was enthroned sometime in 158 BC, his pre-ascension name was Prince Nikohiko Ō-hibi no Mikoto. The Kojiki records that he ruled from the palace of Sakaihara-no-miya (軽之堺原宮, and in the Nihon Shoki as 軽境原宮) at Karu in what would come to be known as Yamato Province. Emperor Kaika had a chief wife (empress) named Ikagashikome, along with three consorts of which he fathered five children with. Kaika ruled until his death in 98 BC; his second son was then enthroned as the next emperor. His son/heir to the throne was posthumously named Sujin by later generations, and is the first emperor that historians say might have actually existed.
The existence of at least the first nine Emperors is disputed due to insufficient material available for further verification and study. Kaika is thus regarded by historians as a "legendary Emperor", and is considered to have been the eighth of eight Emperors without specific legends associated with them.[b] The name Kaika-tennō was assigned to him posthumously by later generations.  His name might have been regularized centuries after the lifetime ascribed to Kaika, possibly during the time in which legends about the origins of the Yamato dynasty were compiled as the chronicles known today as the Kojiki. While the actual site of Kaika's grave is not known, the Emperor is traditionally venerated at a memorial Shinto shrine (misasagi) in Nara. The Imperial Household Agency designates this location as Kaika's mausoleum, and its formal name is Kasuga no Izakawa no saka no e no misasagi.
Like Emperor Kōshō and Emperor Kōrei, there is a possibility that "Kaika" could have lived instead in the 1st century (AD). Historian Louis Frédéric notes this idea in his book Japan Encyclopedia where he says "more likely early AD", but this remains disputed among other researchers. The first emperor that historians state might have actually existed is Emperor Sujin, the 10th emperor of Japan. Outside of the Kojiki, the reign of Emperor Kinmei[c] (c. 509 – 571 AD) is the first for which contemporary historiography is able to assign verifiable dates. The conventionally accepted names and dates of the early Emperors were not confirmed as "traditional" though, until the reign of Emperor Kanmu[d] between 737 and 806 AD.
Consorts and children
Empress: Ikagashikome (伊香色謎命), Oohesoki's daughter
- Second Son: Prince Mimakiirihikoinie (御間城入彦五十瓊殖尊), later Emperor Sujin
- Princess Mimatsuhime (御真津比売命)
Consort: Taniwanotakano-hime (丹波竹野媛), Taniwa no Ooagatanushi Yugori's daughter
- First Son: Prince Hikoyumusu (彦湯産隅命)
Consort: Hahatsu-hime (姥津媛), Prince Waninishisaihito's daughter
- Third Son: Prince Hikoimasu (彦坐王)
Consort: Washi-hime (鸇比売), Katsuragi no Tarumi no Sukune's daughter
- Prince Taketoyohazurawake (建豊波豆羅和気王)
- "Genealogy of the Emperors of Japan" (PDF). Kunaicho.go.jp. Retrieved May 16, 2019.
- Kenneth Henshall (2013). Historical Dictionary of Japan to 1945. Scarecrow Press. p. 487. ISBN 9780810878723.
- Ponsonby-Fane, Richard (1959). The Imperial House of Japan. Ponsonby Memorial Society. p. 30 & 418.
- "開化天皇 (9)". Imperial Household Agency (Kunaichō) (in Japanese). Retrieved May 16, 2019. Italic or bold markup not allowed in:
- Brown, Delmer M. and Ichirō Ishida (1979). A Translation and Study of the Gukanshō, an Interpretative History of Japan Written in 1219. University of California Press. p. 252. ISBN 9780520034600.
- Nussbaum, Louis-Frédéric (2002). Japan Encyclopedia. Harvard University Press. p. 451. ISBN 9780674017535.
- Yoshida, Reiji. (March 27, 2007). "Life in the Cloudy Imperial Fishbowl". The Japan Times Online. Japan Times. Retrieved May 17, 2019.
- Kelly, Charles F. "Kofun Culture". www.t-net.ne.jp. Retrieved May 17, 2019.
- Aston, William George. (1896). Nihongi: Chronicles of Japan from the Earliest Times to A.D. 697, Volume 2. The Japan Society London. p. 109, 148–149.
- Brinkley, Frank (1915). A History of the Japanese People from the Earliest Times to the end of the Meiji Era. Encyclopaedia Britannica Company. p. 21.
Posthumous names for the earthly Mikados were invented in the reign of Emperor Kanmu (782–805), i.e., after the date of the compilation of the Records and the Chronicles.
- Miller, R. A. (2003). "Journal of Asian History". Journal of Asian History. 37 (2): 212–214. JSTOR 41933346.
Review of Japan Encyclopedia
- Titsingh, Isaac. (1834). Nihon Ōdai Ichiran (in French). Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland. p. 34–36.
- Brown, Delmer M. and Ichirō Ishida (1979). A Translation and Study of the Gukanshō, an Interpretative History of Japan Written in 1219. University of California Press. p. 261–262. ISBN 9780520034600.
- Hoye, Timothy. (1999). Japanese Politics: Fixed and Floating Worlds. Prentice Hall. p. 78. ISBN 9780132712897.
According to legend, the first Japanese Emperor was Jimmu. Along with the next 13 Emperors, Jimmu is not considered an actual, historical figure. Historically verifiable Emperors of Japan date from the early sixth century with Kimmei.
- 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
- Chamberlain, Basil Hall. (1920). The Kojiki. Read before the Asiatic Society of Japan on April 12, May 10, and June 21, 1882; reprinted, May, 1919. OCLC 1882339
- Nussbaum, Louis-Frédéric and Käthe Roth. (2005). Japan encyclopedia. Cambridge: Harvard University Press. ISBN 978-0-674-01753-5; OCLC 58053128
- Ponsonby-Fane, Richard Arthur Brabazon. (1959). The Imperial House of Japan. Kyoto: Ponsonby Memorial Society. OCLC 194887
- Titsingh, Isaac. (1834). Nihon Ōdai Ichiran; ou, Annales des empereurs du Japon. 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
| Legendary Emperor of Japan
158 BC – 98 BC