徳川家定
In September 1843, Abe became "rōjū" at the young age of 25, moving his residence to the Abe family's estate at Tatsunokuchi, outside Edo Castle (modern day Ōtemachi). He became "rōjū shuza" (老中首座, presiding senior councillor) in September 1845, after Mizuno Tadakuni lost his standing over the failure of the Tenpō Reforms. Abe held this position throughout the administrations of Shōgun Tokugawa Ieyoshi and Tokugawa Iesada, working to unify shogunal politics.