Emperor Ingyo (允恭天皇)
Emperor Ingyo (circa 376 - February 8, 453) was the nineteenth Emperor of Japan (reigned from January, 413, to February 8, 453). His names include Oasazuma wakugo no sukune no mikoto and Oasazuma wakugo no sukune no miko (according to "Kojiki" [literally, The Records of Ancient Matters]). He is identified with the king of Wa (supposedly, Japan), King Sai, of the five kings of Wa, described in the Chinese history books, "So-jo" (which is known as "Sung-shu" in Chinese or the Book of Song [one of the Southern Dynasties of China]) and "Ryo-jo" (known as "Liang-shu" in Chinese or the Book of Liang).
Genealogy
Oasazuma wakugo no sukune no miko (the future Emperor Ingyo) was the fourth son (prince) of Emperor Nintoku. His mother was a daughter of KATSURAGI no Sotsuhiko, whose name was Iwanohime no mikoto.
He was a younger brother of Emperors Richu and Hanzei.
Imperial Palace
It was Totsu asuka no miya Palace in the capital (located presumably in present-day Asuka, Asuka-mura Village, Takaichi-gun County, Nara Prefecture.)
The first Emperor who built a palace in Asuka was Ingyo.
Background
The followings are based on "Nihonshoki" (Chronicles of Japan).
Since Emperor Hanzei passed away in February, 410, without naming the Crown Prince, a crowd of retainers conferred together and recommended Oasazuma wakugo no sukune no mikoto as the Emperor (okimi). He repeatedly refused to accept the emperorship on the ground of being ill, so that the throne remained vacant, but in January, 413, upon strong request from Oshisaka no onakatsu hime no mikoto, he finally acceded to the throne.
In September, 413, a doctor was invited from Silla (ancient Korean kingdom) to treat illness of the Emperor.
In October, 416, in order to resolve a confusion in the Uji-kabane system (the system of clans and hereditary titles) among various clans, the Emperor carried out Kugatachi ordeal (also known as kukatachi or kukadachi, which refers to hot-water ordeal) at Amakashi no oka Hill in Asuka.
In August, 416, Tamada no sukune (grandson of KATSURAGI no Sotsuhiko) turned out to be rebellious, and the Emperor punished him by death.
In January, 419, the Emperor made Sotooshi (also read Sotoori) no iratsume, a younger sister of the Empress, enter into court (which was called judai, meaning an imperial consort's bridal entry into court), but this fell under the Empress's displeasure, and he made Sotooshi no iratsume live in the Fujiwara no miya Palace (in present-day Kashihara City, Nara Prefecture).
In March, 419, Sotooshi no iratsume who feared the jealous Empress moved to Chinu no miya Palace (in present-day Izumisano City, Osaka Prefecture).
Emperor continued the imperial visit to iratsume using hunting as his excuse, but in 421, he was warned by the Empress, thereafter rarely visiting Chinu.
In July, 435, an incest between the Crown Prince Kinashi no karu no miko and his younger sister, Karu no oiratsume, was brought to light.
Karu no oiratsume was exiled to Iyo Province (see Sotoori-hime legend)
He passed away in February, 453. The king of Silla mourned the demise and sent a messenger of condolence. His age at demise was 78 according to "Kojiki" and "Kujiki" (an ancient Japanese historical text), 80 according to "Gukansho" (Jottings of a Fool) and "Jinno Shotoki" (Chronicle of Gods and Sovereigns), and 81 according to the Kitano manuscript (the Kitano Ms., Class I, owned by Kitano-tenmangu Shrine in Kyoto) of the "Nihonshoki" (68 according to the unknown reference cited therein).
A Theory of Emperor Ingyo Being Gozoku
There is some peculiarity in the name of Emperor Ingyo. That is, his name Oasazuma wakugo no sukune no mikoto includes the title of honor, 'Sukune,' which does not fit for an Imperial (or royal) Family member. The title Sukune (which was written as "宿禰" or "足尼" in Japanese) was, particularly from the fourth century to the sixth, often added after the name of influential gozoku (local ruling families, who are not related to the royal family) (e.g., NOMI no Sukune, TAKENOUCHI no Sukune, TAKARI no Sukune and so on). Therefore, there is a theory which regards the Emperor Ingyo as originally being a member of gozoku from Katsuragi (Gose City, Nara Prefecture), and presumed that after the death of Emperor Hanzei, he may possibly have usurped the throne. Collateral evidences for that include: a fact that his name is fundamentally different from those of Richu and Hanzei which bear the title of wake (which means 'coming into being'); a legend that he was despised by these two Emperors as a fool because of his illness and his accession to the throne did not proceed smoothly; a story told in genealogies of Soga and Katsuragi clans which were the influential Gozoku of the time that there was reportedly a person known as WAKUGO no Sukune who was a son of TAKENOUCHI no Sukune at a period which overlaps that of Ingyo; and a problem in the "So-jo" (the Book of Song) that it does not describe any blood relationship between King Sai of Wa (Ingyo) and King Chin of Wa (identified with Hanzei).
Imperial Tomb and Mausoleum
He was entombed in Ega no nagano no kita no misasagi (mausoleum). The mausoleum is identified with Kokufu Ichinomiya kofun (tumulus) (a large keyhole-shaped tumulus of 228 meters in the total length) located at 1-chome, Kokufu, Fujiidera City, Osaka Prefecture.