Emperor Jimmu; also known as: Kamuyamato Iwarebiko; given name: Wakamikenu no Mikoto or Sano no Mikoto, was the first emperor of Japan, according to the traditional order of succession.
The Imperial house of Japan traditionally based its claim to the throne on its descent from Jimmu. No firm dates can be assigned to this early emperor's life or reign, nor for the reigns of his early successors. The reign of Emperor Kimmei (509-571), the 29th emperor of Japan according to the traditional order of succession, is the first for which contemporary historiography are able to assign verifiable dates.
According to the legendary account in the Kojiki, this historical figure would have been born on February 13, 711 BC (the first day of the first month of the Chinese calendar), and died, again according to legend, on March 11, 585 BC (both dates according to the lunisolar traditional Japanese calendar).
The conventionally accepted names and dates of the early emperors were not to be confirmed as "traditional" until the reign of Emperor Kammu (737-806), the 50th sovereign of the Yamato dynasty.
According to Shinto belief, Jimmu is regarded as a direct descendant of the sun goddess, Amaterasu. Amaterasu had a son called Ame no Oshihomimi no Mikoto and through him a grandson named Ninigi-no-Mikoto. She sent her grandson to the Japanese islands where he eventually married Konohana-Sakuya-hime. Among their three sons was Hikohohodemi no Mikoto, also called Yamasachi-hiko, who married Toyotama-hime. She was the daughter of Ryuujin, the Japanese sea god. They had a single son called Hikonagisa Takeugaya Fukiaezu no Mikoto. The boy was abandoned by his parents at birth and consequently raised by Tamayori-hime, his mother's younger sister. They eventually married and had a total of four sons. The last of them became Emperor Jimmu.
It is said that soon after the beginning of Jimmu's reign, a Master of Ceremonies (saishu) was appointed. This office was commonly held by a member of the Nakatomi clan after the eighth century.