Although Iemochi was only thirteen at the time he became shogun, since he was a cousin of the 13th shogun Iesada TOKUGAWA and more closely related to the former shogun, he was chosen even over Yoshinobu whose blood relationship ran back to Ieyasu TOKUGAWA, the first shogun of Tokugawa family.
家茂はこの時13歳という若年であったが、第13代将軍・徳川家定の従兄弟に当たり前将軍の最近親ということから、血縁を徳川初代の徳川家康まで遡らなくてはならない慶喜を抑えて将軍に就任したのである。