The Ansei Purge

The Ansei Purge followed the 1858 treaty and shogunal-succession disputes. Ii Naosuke’s government faced criticism of signing without imperial approval and of choosing Yoshitomi, later Iemochi, over Hitotsubashi Yoshinobu. A court decree sent directly to Mito supplied another conflict over channels of authority.

Arrests began in Kyoto and Edo, and prisoners were transferred for judgment. Daimyo and courtiers received confinement or forced retirement, while retainers and activists faced imprisonment and, in some cases, death sentences. Hashimoto Sanai and Yoshida Shōin were executed in 1859. Umeda Unpin died in prison before the final executions; he was not one of those put to death by sentence.

The punished included officials favorable to foreign negotiation as well as advocates of expulsion. Their disputes with Ii cannot be reduced to one shared policy. Repression removed particular opponents while leaving the underlying treaty and court conflict unresolved. In 1860, Mito-linked rōnin attacked and killed Ii outside Sakurada Gate, carrying that conflict into violence at the castle’s entrance.