徳川家宣
In 1693, Hakuseki was called up to serve by the side of Manabe Akifusa as a "brain" for the Tokugawa shogunate and shogun Tokugawa Ienobu. He went on to displace the official Hayashi advisers to become the leading confucianist for Ienobu and Tokugawa Ietsugu. While some of Hakuseki's policies were still carried out after Ienobu's death, after the 6th shogun, Tokugawa Ietsugu, died and Tokugawa Yoshimune's rule began, Hakuseki left his post to begin his career as a prolific writer of Japanese history and Occidental studies.