Kyoto Shoshidai
Tadaaki was fifth son of Sakai Tadayuki, and became "daimyō" in 1834 on the retirement of Sakai Tadayori without an heir. His wife was a daughter of Matsudaira Terunobu of Takasaki Domain. In 1840, he was given the courtesy title of "Wakasa-no-kami" and Lower 4th, Junior grade court rank. In 1842, was appointed a "sōshaban" and "jisha-bugyō" simultaneously. The following year was appointed the 48th "Kyoto Shoshidai", and added the title of "Jijū" to his honorifics. Owing to his opposition of the candidacy of Tokugawa Yoshitomi (the later shōgun Iemochi) for the position of "shōgun", he angered the political faction within the government which supported Hitotsubashi Yoshinobu. This was one of the causes of Ii Naosuke's Ansei Purge, and Tadaaki was forced to resign as "Kyoto Shoshidai" in 1850.