Ii Naosuke

Who They Were

Ii Naosuke (井伊直弼, いい なおすけ) was a daimyō, a feudal lord, of Hikone domain from 1850 until his death in 1860. He also served as Tairō, the highest-ranking official in the Tokugawa shogunate, from April 23, 1858, until he was assassinated on March 24, 1860. Born on November 29, 1815, he lived through the final years of the Edo period (1603–1868), a time when the shogunate faced mounting pressure from foreign powers and internal political crisis.

He was the son of Ii Naonaka, and a member of the Ii clan, a fudai daimyo house—one of the hereditary vassal families that had supported the Tokugawa shogunate since its founding. His place of birth was Rakuraku-en, a garden residence in Hikone. Beyond politics, Naosuke was a serious and accomplished practitioner of the Japanese tea ceremony, specifically in the Sekishūryū style, and he wrote at least two works on the subject, including Chanoyu Ichie Shū.

Life and Career

Naosuke became daimyō of Hikone in 1850, succeeding to the headship of the Ii clan. His rise to national prominence came during a succession crisis. The shogun, Tokugawa Iesada, was ailing and had no children, and two factions within the shogunate backed different candidates for the next shogun. Naosuke aligned with the Nanki faction, which supported Tokugawa Yoshitomi of the Kii branch of the family. In 1858, he used his authority as Tairō to force through the appointment of Yoshitomi, overriding the opposition of rival lords and court nobles.

That same year, Naosuke signed the Harris Treaty with the United States. The treaty opened Japanese ports to American merchants and seamen and granted extraterritoriality to American citizens, meaning they were subject to American law rather than Japanese law while in Japan. The agreement was deeply unpopular among many samurai and nobles, who saw it as a humiliating concession to foreign powers. Naosuke responded by launching a purge of his political opponents, arresting and executing or imprisoning those who had resisted his policies and his choice of successor.

His hardline approach briefly restored the shogunate's authority, but it also created a wave of resentment. On March 24, 1860, a group of seventeen samurai from Mito domain and one from Satsuma domain ambushed Naosuke outside Sakurada-mon, one of the gates of Edo Castle. He was killed in the attack, an event known as the Sakuradamon Incident.

Why They Matter

Naosuke's decision to sign the Harris Treaty was a turning point in Japanese history. It ended the country's policy of near-total isolation and forced the shogunate to confront the reality of Western military and economic power. The treaty opened the door to similar agreements with other nations and set the stage for the rapid modernization that followed in the Meiji period.

His handling of the succession dispute also mattered. By imposing his chosen candidate as shogun, Naosuke demonstrated that the shogunate could still act decisively, but the purge that followed alienated powerful domains and samurai factions. The Sakuradamon Incident, his assassination, showed that the shogunate could no longer protect its highest officials from violence. That event is often seen as a sign of the shogunate's weakening grip on power in the years before the Meiji Restoration.

Naosuke also left a cultural legacy. His writings on the tea ceremony, including Chanoyu Ichie Shū, reflect a serious engagement with the discipline, and he is remembered as one of the few major political figures of the era who was also a dedicated artist.

The Name in Japanese

The name is written 井伊直弼 in kanji. In kana, it is いい なおすけ. In romaji, it is Ii Naosuke.

• 井 (い, i) — "well" as in a water well. This character is part of the clan name Ii, which is also written with the second character below.
• 伊 (い, i) — a character used phonetically in this name; it has no independent meaning here, though it can refer to Italy or to the pronoun "that" in classical Chinese-derived contexts. Together, 井伊 forms the clan name Ii.
• 直 (なお, nao) — "straight," "direct," "honest." This is the first character of the given name Naosuke.
• 弼 (すけ, suke) — "helper," "assistant," "to aid." This character is common in samurai given names and carries the sense of one who supports or serves. In this name, it is read as suke.

The full name can be understood as "Ii, the honest helper," though the clan name 井伊 is primarily a hereditary designation rather than a descriptive phrase.

Legacy

Naosuke's assassination did not end the conflicts he had set in motion. The Sakuradamon Incident became a rallying point for those who opposed the shogunate and foreign treaties, and it contributed to the political instability that culminated in the Meiji Restoration of 1868. The shogunate itself collapsed less than a decade after his death.

His reputation is mixed. Some historians view him as a pragmatic statesman who recognized that Japan could not resist Western demands and chose to negotiate rather than fight. Others see him as an authoritarian figure whose heavy-handed tactics provoked the very violence that killed him. Both views rest on the same facts: he made a treaty that changed Japan's place in the world, and he died for it.

In Hikone, his memory is preserved. Rakuraku-en, his birthplace, remains a site associated with his life, and his tea ceremony writings continue to be studied by practitioners of the Sekishūryū school. His children, including Ii Naonori and Ii Naoyasu, carried on the Ii clan name after his death.