Ii Naosuke Is Killed outside Sakurada Gate

On the third day of the third month of the Japanese calendar in 1860, attackers struck Ii Naosuke’s procession outside Sakurada Gate in falling snow. Seventeen had left the Mito domain; Arimura Jizaemon came from Satsuma. Seki Tetsunosuke directed the operation. Ii was killed at the entrance to the castle he served.

The plan grew from disputes over succession, treaty approval and the Ansei Purge. Mito opponents also resisted the shogunate’s demand to return the imperial decree sent to their domain. Coordination with a Satsuma participant turned those disputes into an organized attack; it was not an action ordered by the entire Mito domain.

Hasuda Ichigorō, one of the assailants, was wounded and then presented the attackers’ statement at a senior councilor’s residence. While held in another lord’s custody, he drew the clash at retainers’ request; he was executed the following year. That surviving record preserves a participant’s account of the violence. The killing removed Ii, while the continuing sequence of assassinations shows that it did not resolve the regime’s political conflict.