Ansei Purge

In 1858 (Ansei 5), Tairō Ii Naosuke seized total control of the shogunate and unleashed the Ansei Purge, an unprecedented large-scale political persecution. Its targets encompassed all forces opposed to both the succession dispute and the US-Japan Treaty of Amity and Commerce (Harris Treaty) — from sonnō-jōi activists to dissidents within Mito, Chōshū, and Satsuma domains, and even imperial court nobles.

**Background of the Purge: The Succession Question and the Opening of Japan**

The Ansei Purge had two direct triggers. The first was the question of the shogun's succession. The 13th shogun, Tokugawa Iesada, was sickly and had no heir. The "Hitotsubashi faction" — which championed Hitotsubashi Yoshinobu of the Mito Tokugawa house and was backed by major domains including Echizen, Satsuma, and Owari — clashed with the "Nanki faction," which promoted Tokugawa Yoshitomi of Kii (who would later be renamed Iemochi) and was supported by conservative hereditary daimyo including Ii Naosuke himself.

The second trigger was the conclusion of the Harris Treaty. Senior Councilor Hotta Masatake sought imperial sanction from the court, but Emperor Kōmei refused. Nevertheless, in June of Ansei 5, Ii signed the treaty unilaterally without imperial approval. This "unauthorized signature"—a violation of imperial sanction—provoked fierce backlash from the sonnō-jōi faction.

Immediately upon assuming his post as Tairō, Ii Naosuke launched a campaign of suppression against activists, daimyo, and court nobles throughout the realm. His aim was to eliminate the Hitotsubashi faction and contain all opposition to the opening of trade and the unauthorized treaty signing.

**The Persecution of Yoshida Shōin and the Shōka Sonjuku**

One of the victims of the Ansei Purge whose impact would resonate most profoundly through posterity was Yoshida Shōin (1830–1859), a samurai of Chōshū domain. Shōin was a philosopher and educator who, at his Shōka Sonjuku academy in Hagi, cultivated Takasugi Shinsaku, Itō Hirobumi, Yamagata Aritomo, and others. He was an opponent of Japan's opening to foreign trade and a theoretical pillar of the sonnō-jōi movement.

Shōin is said to have plotted the assassination of Senior Councilor Manabe Akikatsu in Ansei 5 (the "Manabe attack plan"), but the shogunate discovered this plot and transported him to Edo. On October 27 of Ansei 6 (1859), Shōin was beheaded at Edo's Denmachō prison. He was twenty-nine years old. His death poem—"Though my body may rot in the fields of Musashi, I leave behind my yamato-damashii"—became a spiritual rallying cry for the activists of the Meiji Restoration.

**The Execution of Hashimoto Sanai and the Persecution of Echizen Domain**

Hashimoto Sanai (1834–1859) of Echizen domain (Fukui) was a brilliant politician and physician who, as the trusted aide of his daimyo Matsudaira Yoshinaga (also known as Haruyoshi), actively championed the Hitotsubashi faction. Though only twenty-five, Sanai had already gained the confidence of the Senior Councilors. He was arrested for his role in supporting Yoshinobu's succession to the shogunate and was beheaded on October 7 of Ansei 6 (1859). He was twenty-six years old.

Matsudaira Haruyoshi, daimyo of Echizen domain, was also placed under house confinement, and leading Hitotsubashi faction daimyo were progressively removed from political authority.

**The Persecution of Mito Domain and the Unraveling of the Council**

Mito domain was the wellspring of sonnō-jōi ideology, and its daimyo, Tokugawa Nariaki, was the most zealous supporter of the Hitotsubashi faction as guardian to his son Hitotsubashi Yoshinobu. Ii Naosuke imposed permanent house confinement on Nariaki and systematically eliminated leading sonnō-jōi figures among Mito domain's samurai.

The purge extended also to the imperial court, where court nobles connected to Kampaku (Chief Adviser) Kujō Hisatada and to the expulsionist factions were punished. Among those over one hundred who suffered punishment were sentences of execution (beheading or death in prison), distant exile, house confinement, and forced retirement.

**Swords and the Purge: The Weapons and Spirit of the Activists**

The Ansei Purge holds profound meaning in the history of Japanese sword culture. For the sonnō-jōi activists subjected to persecution, the Japanese sword was far more than a weapon—it was the embodiment of yamato-damashii, the Japanese spirit. The blades worn by Shōin's disciples were the physical manifestation of the unity of belief and action.

Ii Naosuke, the architect of the Ansei Purge, was himself celebrated as a connoisseur of fine swords. The Ii house took pride in its collection of blades across generations, and Naosuke possessed deep expertise in swordcraft alongside tea ceremony and Nō theater. The blade he would later receive outside the Sakuradamon gate was, with bitter irony, the same "sonnō-jōi sword" worn by the very activists he had crushed.

The swords sought by activists of this era were practical combat blades—long swords and short swords—and the explosive demand of the bakumatsu period brought shinshintō smiths an avalanche of commissions. The lineage of shinshintō established by disciples of Suishinshi Masahide, including Taikei Naotane, came into full flower in the crucible of this sonnō-jōi movement.

**The Conclusion of the Purge and the Chain Toward the Sakuradamon Incident**

The Ansei Purge reached a provisional end by the close of Ansei 6 (late 1859), though its cost was catastrophic. The persecuted Mito domain samurai watched and waited for their moment of vengeance. On March 3 of the following year, Anei 1 (1860), eighteen rōnin from Mito and Satsuma domains ambushed Ii Naosuke's palanquin outside the Sakuradamon gate of Edo Castle in broad daylight—the Sakuradamon Incident.

Ii Naosuke fell nearly instantly. The assassination of the realm's Tairō in full daylight before Edo Castle announced to all that the shogunate's absolute authority had begun to crumble. Paradoxically, the Ansei Purge itself became the initial trigger for the shogunate's ultimate collapse.

From the Ansei Purge through the Sakuradamon Incident and onward through the cascading bakumatsu upheavals—the Ikedaya Incident, the Kinmon Incident, the Battle of Toba-Fushimi—lay a collision between Ii Naosuke's persecution and the activists' yamato-damashii. The Ansei Purge was the darkest night of an age in which the Japanese sword shone brightest as the symbol of the spirit.