The Sakashitamon Gate Incident

On January 15, 1862 (Bunkyu 2), Mito roshi and patriots from various regions attacked and injured the senior councilor Ando Nobumasa outside the Sakashita Gate of Edo Castle. Ando Nobumasa inherited the plan left by the chief councilor Ii Naosuke and realized the marriage of Princess Kazunomiya to Edo, and the wedding was scheduled to take place on February 11 of that year. Prior to this, the extremist factions of the Mito and Choshu clans, which had suffered a major blow in the Ansei Purge, strengthened their ties even after Naosuke's assassination in March 1860 (Man'en 1) (the Sakuradamon Gate Incident), and in July of that year, on the Choshu warship Heishin Maru in Edo Bay, they concluded a pact aimed at reforming the shogunate, and deepened contact with the extremist faction of Satsuma. At the same time, Mito ronin attacked the British Temporary Embassy at Tozenji in May 1666, but they were subjected to further oppression by the shogunate, and the conservative faction gained power within the Mito domain, while the extremist pro-expulsion faction lost ground. The extremist faction of the Mito domain then came up with a plan to directly attack Ando Nobumasa, who had put the shogunate in a favorable position by marrying Princess Kazunomiya to Japan. The plan was carried out by Mito samurai such as Nomura Tsunenosuke, Hara Ichinoshin, Shimono Yajiro, and Sumiya Toranosuke, in cooperation with sonno-joi faction members of the Utsunomiya domain such as Ohashi Totsuan, and patriots from the neighboring province of Shimotsuke (Tochigi Prefecture). Ohashi Nutsuan was a proponent of the restoration of the monarchy who rejected the shogunate. He was the central figure in planning the plan and is said to have also written the petition for the execution of Ando. Other members of the public, including Kikuchi Kyochu, a merchant from Utsunomiya who was Nutsuan's wife's younger brother, Kojima Kyosuke, Oyama Shunzan from Moka in Shimotsuke Province, Yokota Noritsuna and his two children, and Kono Kenzo, participated and cooperated. The plan was discovered in advance and Nutsuan was captured on January 12, but six men, mainly from the Mito domain, including Hirayama Hyosuke and three others, attacked Ando on the 15th, injuring Ando. The Sakashitamongai Incident was not simply an opposition movement against the Ando government, which was considered an imitation of the Ii government, but also a movement critical of the shogunate by those known as the "grassroots people," including those who supported the restoration of the monarchy, such as Ohashi Nutan, and merchants, doctors, and scholars from small provincial towns.

[Hachiro Kawachi]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

1862年（文久2）1月15日、水戸(みと)浪士と各地の志士が、江戸城坂下門外で、老中安藤信正(あんどうのぶまさ)を襲撃し、負傷させた事件。安藤信正は、大老井伊直弼(なおすけ)の遺策を継承して和宮(かずのみや)の江戸降嫁を実現させ、この年2月11日には婚儀が行われることとなっていた。これより先、安政(あんせい)の大獄で大きな打撃を受けた水戸・長州両藩の激派は、60年（万延1）3月の直弼暗殺（桜田門外の変）後も結合を強め、その7月には、江戸湾にあった長州軍艦丙辰(へいしん)丸で、幕閣の改造を目ざす盟約を結び、薩摩(さつま)の激派とも接触を深めた。おりから水戸浪士らは、61年5月、東禅寺英国仮公使館を襲撃したが、幕府のいっそうの弾圧を受けることになり、水戸藩内では保守派が勢力を得て、攘夷(じょうい)激派は立場を失った。そこで水戸藩の激派は、和宮降嫁の実現によって幕府の立場を有利にした安藤信正を直接要撃する計画に向かった。計画は、野村彝之介(つねのすけ)、原市之進(はらいちのしん)、下野隼次郎(しものはやじろう)、住谷寅之介(すみやとらのすけ)らの水戸藩士を中心に、宇都宮藩の尊攘派大橋訥庵(とつあん)ら、隣国下野(しもつけ)（栃木県）の志士との連合で進められた。大橋訥庵は、幕府の否定を説く王政復古論者で、立案の中心人物となり、安藤の斬奸(ざんかん)趣意書も執筆したとされている。訥庵夫人の弟の宇都宮商人菊池教中(きょうちゅう)、同じく児島強介(こじまきょうすけ)、下野国真岡(もおか)の小山春山(おやましゅんざん)、横田祈綱(のりつな)とその2子、河野顕三(こうのけんぞう)ら草莽(そうもう)の士が参画協力した。計画は事前に発覚、訥庵は1月12日に捕らえられたが、平山兵介ら3名の水戸藩士を中心とする6名が、15日に襲撃を決行、安藤を負傷させた。坂下門外の変は、単に井伊政権の亜流とされた安藤政権への反対運動ではなく、大橋訥庵のような王政復古論者や、地方小都市の商人、医師、学者など「草莽」とよばれた者の、幕府批判の運動でもあった。

［河内八郎］

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