The rebellion at the Hamaguri Gate (蛤御門の変 Hamagurigomon no Hen, also 禁門の変 Kinmon no Hen) of the Imperial Palace in Kyōto

Kyoto

is a city in the central part of the island of Honshū, Japan. It has a population close to 1.5 million. Formerly the imperial capital of Japan, it is now the capital of Kyoto Prefecture, as well as a major part of the Osaka-Kobe-Kyoto metropolitan area.-History:...

 took place on August 20, 1864 and reflected the discontent of pro-imperial and anti-alien groups. The rebels were grouped under the Sonnō Jōi

Sonno joi

is a Japanese political philosophy and a social movement derived from Neo-Confucianism; it became a political slogan in the 1850s and 1860s in the movement to overthrow the Tokugawa bakufu, during the Bakumatsu period.-Origin:...

 slogan which had been promulgated by the Emperor as the "Order to expel barbarians

Order to expel barbarians

The was an edict issued by the Japanese Emperor Kōmei in 1863 against the Westernization of Japan following the opening of the country by Commodore Perry in 1854.-The order:...

" in March 1863, and wished to take control of the Emperor himself to accomplish the restoration of the Imperial throne.

During the bloody crushing of the rebellion, the leading Chōshū clan was held responsible for it.

During the incident, the Aizu

Aizu

is an area comprising the westernmost third of Fukushima Prefecture in Japan. The principal city of the area is Aizuwakamatsu.During the Edo period, Aizu was a feudal domain known as and part of Mutsu Province.-History:...

 and Satsuma domains led the defense of the Imperial palace.

The Shogunate followed up the incident with a retaliatory armed expedition, the First Chōshū expedition‎, in September 1864.