Incident outside Sakuradamon (1/2)Naosuke Ii assassination case

On March 3, 1860, the world was shocked. The elder Ii Naosuke was assassinated outside the Sakuradamon gate of Edo Castle (present-day Kasumigaseki, Chiyoda-ku, Tokyo) by roni samurai from the Mito domain. Due to the incident known as the ``Sakurada Mongai Incident,'' the authority of the shogunate fell, leading to the civil wars at the end of the Edo period and the Meiji Restoration. This time, we will provide an easy-to-understand explanation of the Sakuradamongai Incident, which was a major turning point in history and is said to be the cause of the Meiji Restoration.

Why did the incident outside Sakuradamon occur? Reason and background

The Sakuradamon Incident was a major incident in which Naosuke Ii, the leader of the Shogunate government, was murdered in front of Edo Castle. Why did this incident occur? The reason for this was the social situation at the time.

At the end of the Edo period, the shogunate faced two major problems. One was the issue of the successor to the 13th shogun, Tokugawa Iesada, who was in poor health. Another problem was the issue of how to respond to pressure from other countries to open the country and trade after the arrival of the black ships in 1853.

Regarding the issue of successor, it was a one-on-one battle between Yoshifuku Tokugawa (Iemochi), the lord of the Kii domain who had a close lineage to the shogunate, and Yoshinobu Hitotsubashi, known as a wise man (who actually competed with Iesada for the position of 13th generation). The ``Nanki faction,'' which supported Keifuku, was a conservative and moderate faction that held the initiative in politics, and was mainly made up of Fudai daimyo and people from Ooku. Naosuke Ii, the lord of Hikone, who was assassinated during the Sakuradamon Incident, was a member of the Nanki school. On the other hand, the Hitotsubashi faction, which supported Yoshinobu, had many people who supported the opening of the country and the Joi faction, and were mainly Tozama daimyo. The main members included Nariaki Tokugawa, Yoshinobu's father and the lord of the Mito domain, and Nariaki Shimazu, the lord of the Satsuma domain. These two factions were in conflict.

Regarding foreign relations, the shogunate began by concluding the Treaty of Peace and Amity between Japan and the United States in March 1854, and opened the country by signing similar treaties with Great Britain, the Russian Empire, and the Netherlands. However, ports were limited and trade was not permitted. However, U.S. Consul General Townsend Harris appealed for the start of trade between Japan and the United States and put pressure on the Shogunate. The shogunate moved toward concluding a trade treaty, but the person who stood in its way was Emperor Komei, known for hating foreign countries. ``Japanese relations'' were allowed, but ``commerce'' was not allowed.

Meanwhile, in April 1858, Ii Naosuke was appointed as Tairo. Without the permission of the Emperor, Naosuke concludes treaties of amity and commerce with the United States, the Netherlands, the Russian Empire, Great Britain, and France. Additionally, in June, Tokugawa Keifuku was chosen as his successor.

The Hitotsubashi faction strongly opposed this move. Therefore, Naosuke begins to suppress those who oppose his policies, including the Hitotsubashi faction. Nariaki Tokugawa and others were punished by forcing them to retire, and this wasGreat prison of Ansei” (see separate article for details).

The trigger for the incident outside Sakuradamon: “The Secret Edict of Bogo”

The cause of the Ansei Great Prison, which initially limited the punishment to the top officials involved, became more severe, and one of the factors that led to the Sakuradamongai Incident was the Emperor's ``Bogo no Mitsu Edict.'' Emperor Komei was deeply angry that the shogunate had concluded a treaty of amity and commerce without permission. In particular, his anger towards the leader of the shogunate, Naosuke Ii, was so deep that he wanted to abdicate the throne and protest against the shogunate. In fact, Naosuke was against concluding a treaty of amity and commerce without the permission of the Emperor, but this fact was not conveyed to Emperor Komei.

On August 8, the Emperor, furious with the shogunate, sent an imperial edict that should have been sent to the shogunate via the Kanpaku, Hisatada Kujo, directly to the Mito domain, without going through the Kanpaku, and ordered it to be passed on to the various domains. The contents of the imperial edict, known as the ``Bougo no Mitsukyoku,'' included strong criticism of the conclusion of a trade treaty without the Emperor's permission, consideration for the top leaders of the Mito and Owari clans who had been forced to retire and live in seclusion, and the concerns of the three Gosanke families and other clans. The idea was to cooperate with the shogunate and deal with the situation in a way that would not be looked down upon by other countries through a ``komu-gatai'' system in which the imperial court and shogunate became one. In addition, ``copies'' were also transmitted to the Choshu and Satsuma clans through related court nobles.

The imperial edict was also delivered to the Shogunate two days after the Mito domain, but the major problem was that it was notified to the Mito domain before the Shogunate. This is because the shogunate was the point of contact for the imperial court, and the rule was that the shogunate sent notifications to the various clans. There was a suspicion that the Mito clan was trying to replace the Shogunate. There is also a leak that the reason behind the secret edict was the influence of the Mito clan, so Naosuke thoroughly searches for and punishes those involved in the Bogo no Mito edict. Nariaki Tokugawa was forced to live in captivity for a long time, and Tateto Yasushima, a chief retainer of the Mito clan, was forced to commit seppuku.

In this way, Naosuke punished those involved in the secret edicts of the Mito domain one after another, intensifying the Great Prison of Ansei. The people who were oppressed at this time ranged from patriots to daimyo, court nobles, and members of the imperial family, and more than 100 people received some form of punishment. In addition, the shogunate asked the Mito domain to return the secret edict.

Incident outside Sakuradamon ① Deep anger of the Mito clan

The Hitotsubashi faction, especially the Mito clan, was very angry at Ansei's Great Prison, and they began to hold a grudge against Naosuke Ii. Originally, the Mito domain was divided into two groups: the son-no-joi school and the moderate group that valued the relationship between the shogunate. In the midst of this, the shogunate demanded the return of the imperial edict, and a dispute ensued between the moderate factions of the return and the opposition, who were trying to enforce sonno-joi. Among them, the extremist faction of Sonno-joi-ha gathered together several times and plotted to spread the secret imperial edict to various domains. The central figure is Jiro Kinzoku, the ringleader of the Sakuradamongai Incident.

As a result of the Ansei Taigoku punishment, the majority of the Mito domain turned to favoring the return of the imperial clan, but those opposed to the return stubbornly refused and the opposition movement intensified. It began to resemble a civil war, with members of the Denno faction being assassinated and attacked. The Mito clan tries to calm down the situation, but the extremists plan to assassinate Naosuke Ii and go into hiding. In the end, I ended up holding the spark inside.

Incident outside Sakuradamon ② Was the Satsuma clan closely involved at first?

The main perpetrators of Naosuke Ii's assassination were the samurai samurai of the Mito domain, but the Satsuma domain was also very enthusiastic about the assassination plan at first. Shimazu Nariakira, who was punished at the beginning of the Great Prison of Ansei, plans to take 5,000 clan soldiers to Kyoto in protest! However, he died soon after. It is said that he died due to cholera, but there is also a theory that he was poisoned due to the timing.

In response to this, young patriots in the Satsuma domain began working to carry on Nariakira's legacy. The extremist group that later came to be known as the ``Seitagumi'' planned to assassinate Naosuke Ii. Among this group were Toshimichi Okubo and Takamori Saigo, who was hiding on Amami Oshima in an attempt to escape from the great prison of Ansei. They call Naosuke Ii's assassination "prominent" and steadily advance preparations. Approximately 40 people supported the event, and preparations were in full swing. At the final stage, he informed Shigehisa Shimazu (Tadayoshi), who succeeded Nariakira as the lord of the Satsuma domain, of his determination to break away from the domain.

However, the Satsuma domain put a stop to the Seitada-gumi. Shigehisa's father, Hisamitsu Shimazu, who was at the helm, was concerned that it would be bad for a young man to act recklessly at this timing. The words of the feudal lord, Shigehisa, persuade him to refrain from prominence. He praised the ``prominent'' planners as ``Seitada no Shishi'' (the origin of the ``Seituda-gumi''), and declared that he would carry out Nariakira's will and be ``loyal to the Imperial Court'' on the occasion of the arrival of the Great Change. This deterred the Seitada-gumi from attempting to assassinate Naosuke Ii. The assassination plotters returned to the Satsuma domain, but the brothers Yusuke Arimura and Jizaemon did not return to the domain and continued to participate in the plan.

Incident outside Sakuradamon ③ Assassination of Naosuke Ii

Then, on March 3, 1860, the Sakuradamongai Incident occurred. This day was Kamishi no Sekku, now known as Doll's Festival, and was an official event for the shogunate. Daimyo visited Edo Castle every year to greet the shogun, and many commoners gathered to watch the parade of daimyo visiting Edo Castle. The official event was a great opportunity for Mito Roshi and his group aiming to kill Naosuke, as they could blend in with the crowd and get closer to the procession.