The trend of the keyhole kofun first spread from Yamato to Kawachi (where very large kofun such as Daisenryō Kofun exist) and then throughout the country (with the exception of the Tōhoku region) in t...The trend of the keyhole kofun first spread from Yamato to Kawachi (where very large kofun such as Daisenryō Kofun exist) and then throughout the country (with the exception of the Tōhoku region) in the 5th century. The last two great kofun are the Imashirozuka Kofun of Osaka, which is believed by current scholars to be the tomb of Emperor Keitai, and the Ikatoyama Kofun of Fukuoka, recorded in Fudoki of Chikugo to be the tomb of Iwai, the political archrival of Keitai.
