Ii Naosuke

Ii Naosuke was appointed tairo under Shogun Tokugawa Iesada. He took power during a succession dispute and used his authority to force through the shogunate's choice of successor, Tokugawa Iemochi, against the wishes of powerful daimyo.

Ii Naosuke signed the Treaty of Amity and Commerce with the United States, opening five Japanese ports to foreign trade and granting extraterritorial rights to Americans. This unequal treaty was signed without imperial approval, sparking widespread opposition and weakening the shogunate's legitimacy.

To suppress opposition to the treaty and his political maneuvers, Ii Naosuke launched the Ansei Purge, arresting and executing or exiling dozens of rival daimyo, court nobles, and samurai. This brutal crackdown silenced dissent but created deep resentment against the shogunate.

Ii Naosuke was assassinated by a group of ronin samurai from Mito and Satsuma domains outside the Sakurada Gate of Edo Castle. His death marked a turning point, weakening the shogunate's authority and accelerating the collapse of the Tokugawa regime.