Yamato Takeru, originally Prince Ousu, was a Japanese legendary prince of the Yamato dynasty, son of Emperor Keikō, who is traditionally counted as the 12th Emperor of Japan. His name written in kanji can vary, in the Nihon Shoki it is spelled 日本武尊 and in the Kojiki it is 倭建命.
The story of his life and death are told principally in the Japanese chronicles in the late 14th century Kojiki and Nihon Shoki, but also mentioned in Kogo Shūi and some histories like the Hitachi no Kuni Fudoki. One of his sons became Emperor Chūai, the 14th Emperor of Japan.
His history is uncertain but based on the chronicles his life can be calculated. He was born circa 72 and died in 114. Details are different between the two books, and the version in Kojiki is assumed to be loyal to the older form of this legend.