The Ōtomo clan were warriors and bureaucrats in the Yamato Court, and Yakamochi served as a provincial governor in several provinces. Like his grandfather and father before him, Yakamochi was a well-known politician, and by Enryaku rose to the position of chūnagon, his highest bureaucratic position. In 738, he met Udoneri, and in 740 at the behest of Emperor Shōmu went to Dazaifu to suppress the rebellion of Fujiwara no Hirotsugu. In 745 he became a jōgoika. In July of the following year, he became governor of Etchū Province, a post he lasted in until 751. By this time he was already the author of 220 waka. In 751 he was promoted to shōnagon and returned to the capital. In 754 he was appointed military commander, and the following year concerned himself with the garrison at Nanba, a time that is described in the Sakimori Songs Collection in the Man'yōshū. Yakamochi did not take part in the Tachibana no Naramarorebellion. Instead, he conspired with Fujiwara no Yoshitsugu, Isonokami Yakatsugu and Saeki no Imaemishi to plot the assassination of Fujiwara no Nakamaro. Afterwards Yoshitsugu took sole responsibility for the affair, but due to suspicions about Yakamochi's involvement he was transferred to the governorship of Satsuma Province. In 777 he rose to the governorship of Ise Province. According to the records of the Ise Shrine, he served in this post for about five years. In 780 he was promoted to councillor. Fearing suspicion and banishment from the capital for aiding in Hikami no Kawatsugu's rebellion, he remained quiet and was promoted to chūnagon in 783. He died by drowning in Mutsu Province while attending to his concurrent post as shōgun. Soon after his death, Fujiwara no Tanetsugu was assassinated; suspecting that Yakamochi was involved in the affair, his burial was denied and he was posthumously disgraced and excommunicated. His son was stripped of rank and forced into exile, and it was only in 806 that he regained his rank.
Poetic works
Yakamochi was one of the compilers of the Man'yōshū, the first poetry anthology created in Japanese history, for which he not only wrote several poems but also transcribed, rewrote, and refashioned an unknown number of ancient poems and folklore. He was the most prolific and prominent writer of his time, and had a great influence on the Shika Wakashū as well. The famous Gunka song Umi Yukaba used one of his most famous and outstanding poem as lyrics, and was considered Japan's second anthem during wartime. He wrote a eulogy for Prince Asaka.
