Fearing the renewed strengthening of the Tokugawa shogunate under a strong and wise ruler, samurai from
Satsuma,
Chōshū and
Tosa formed an alliance to counter it. Under the banner of
sonnō jōi ("revere the Emperor, expel the barbarians!") coupled with a fear of the new
shōgun as the "Rebirth of
Ieyasu" () who would continue to usurp the power of the Emperor, they worked to bring about an end to the shogunate, though they varied in their approaches. In particular, Tosa was more moderate; it proposed a compromise whereby Yoshinobu would resign as
shōgun, but preside over a new national governing council composed of various
daimyōs. To this end, Yamanouchi Toyonori, the lord of Tosa, together with his advisor,
Gotō Shōjirō, petitioned Yoshinobu to resign in order to make this possible. On 9 November 1867, Yoshinobu tendered his resignation to the Emperor and formally stepped down ten days later, returning governing power to the Emperor. He then withdrew from Kyoto to
Osaka. However, Satsuma and Chōshū, while supportive of a governing council of
daimyōs, were opposed to Yoshinobu's leading it. and moved a massive number of Satsuma and Chōshū troops into Kyoto. There was a meeting called at the imperial court, where Yoshinobu was stripped of all titles and land, despite having taken no action that could be construed as aggressive or criminal. Any who would have opposed this were not included in the meeting. at the urging of the leaders of Aizu, Kuwana, and other domains, and in light of the immense number of Satsuma and Chōshū troops in Kyoto, he dispatched a large body of troops to convey this message to the court. When the Tokugawa forces arrived outside Kyoto, they were refused entry, and were attacked by Satsuma and Chōshū troops, starting the
Battle of Toba–Fushimi, the first clash of the
Boshin War. Though the Tokugawa forces had a distinct advantage in numbers, Yoshinobu abandoned his army in the midst of the fight once he realized the Satsuma and Chōshū forces raised the Imperial banner, and escaped to
Edo. He placed himself under voluntary confinement, and indicated his submission to the imperial court. However, a peace agreement was reached wherein
Tayasu Kamenosuke, the young head of a branch of the Tokugawa family, was adopted and made Tokugawa family head; On 11 April 1868, Edo Castle was handed over to the imperial army, and the city spared from all-out war. Together with Kamenosuke (who took the name
Tokugawa Iesato), Yoshinobu moved to
Shizuoka.
Tokugawa Ieyasu, founder of the Tokugawa Shogunate, had also retired to Shizuoka, centuries earlier. Iesato was made the
daimyō of the new
Shizuoka Domain, but lost this title a few years later, when the domains were abolished. Even after losing his position as ruling shogun, Yoshinobu strove to promote his son Iesato's political career so that he could attain the highest level of influence in the Japanese Imperial court, and also serve as a bridge between old world Japan and modern emerging Japan both domestically and internationally. The close relationship between father and son is highlighted in the illustrated biography on Prince Tokugawa Iesato titled
The Art of Peace. Many of the
hatamoto also relocated to Shizuoka; a large proportion of them did not find adequate means to support themselves. As a result, many of them resented Yoshinobu, some of them to the point of wanting him dead. Yoshinobu was aware of this, and was so afraid of assassination that he redesigned his sleeping arrangement to confuse any potential assassin. ==Later life==