Tokugawa Iemochi
Following a coup d'état within Chōshū which returned to power the extremist factions opposed to the shogunate, the shogunate announced its intention to lead a Second Chōshū expedition to punish the renegade domain. This, in turn, prompted Chōshū to form a secret alliance with Satsuma. In the summer of 1866, the shogunate was defeated by Chōshū, leading to a considerable loss of authority. In late 1866, however, first "shōgun" Tokugawa Iemochi and then Emperor Kōmei died, succeeded by Tokugawa Yoshinobu and Emperor Meiji respectively. These events, in the words of historian Marius Jansen, "made a truce inevitable".