Emperor Yūryaku in the context of "List of emperors of Japan"

Japan has been ruled by emperors since antiquity. The sequence, order and dates of the early emperors are almost entirely based on the 8th-century Nihon Shoki, which was meant to retroactively legitimise the Imperial House by dating its foundation further back to the year 660 BC. Emperor Kinmei (r. 539–571) is often considered the first historical emperor, but the first Japanese ruler supported by historical evidence is actually Emperor Yūryaku (r. 456–479), who is mentioned in the 5th-century Inariyama and Eta Funayama Swords. According to Chinese sources, the unification of Japan took place between the 2nd and 3rd centuries.

The terms Tennō ('Emperor', 天皇), as well as Nihon ('Japan', 日本), were not adopted until the late 7th century AD. In the nengō system which has been in use since the late 7th century, years are numbered using the Japanese era name and the number of years which have elapsed since the start of that nengō era.

Toyouke-hime (豊宇気毘売, Toyouke-bime; lit. "Luxuriant Food Princess") is the deity (kami) of food and grain in the Shinto religion. Originally enshrined in the Tanba region of Japan, it is said she was called to reside at Gekū, Ise Shrine in the 5th century during the reign of Emperor Yūryaku to offer sacred food to Amaterasu Ōmikami, the Sun Goddess.

While popular as Toyouke-Ōhmikami presently, her name has been transcribed using Chinese characters in several manners including Toyouke bime no kami (豊宇気毘売神) in the Kojiki, while there is no entry about her in the Nihon Shoki.

Emperor Kinmei (欽明天皇, Kinmei-tennō; 509–571) was the 29th emperor of Japan, according to the traditional order of succession. His reign is said to have spanned the years from 539 to 571. Most historians support either the view that Kinmei is the first historically verifiable Japanese emperor or the view that Yuryaku (the 21st) is.