A Palace Coup Expels Chōshū and Seven Courtiers

Aizu and Satsuma acted against Chōshū’s influence at the imperial court in 1863. Both supported cooperation between court and shogunate, while Chōshū and allied courtiers promoted a more forceful expulsion policy. Control of access to the palace made the dispute immediately actionable.

On the eighteenth day of the eighth month of the Japanese calendar, palace gates were guarded and notices announced the exclusion of Chōshū and its allies. Matsudaira Katamori’s protectorate supplied armed strength. Sanjō Sanetomi and six other courtiers left Kyoto with Chōshū forces, taking refuge in the domain.

A contemporary city official’s diary records the sudden mobilization: notices reached domain residences and liaison officers, and armed Mibu rōnin passed through the streets. The diarist acknowledged that he did not initially know the cause. The record conveys the operation seen from the city, rather than an account of every secret negotiation. The coup removed one group’s access to the emperor; Chōshū’s attempt to regain its standing helped bring renewed fighting in 1864.