English Version
Oda Nobunaga, famously nicknamed the Demon King of the Sixth Heaven, was killed by his retainer Akechi Mitsuhide in the event known as the Honno-ji Incident. In Japan, it is one of the historical episodes most people learn about in school, and it remains popular in manga, TV dramas, and historical fiction.
But the Honno-ji Incident is not remembered only as a simple betrayal by Mitsuhide. It is also famous as a mystery filled with possible schemes, hidden motives, and unanswered questions. This article introduces several theories that may help explain what really happened.
Why Is the Incident So Mysterious?
Oda Nobunaga was feared for his harsh attitude and his willingness to cut people off without mercy. At the same time, he had overwhelming charisma and was supported by many powerful retainers.
So the greatest mystery is this: why did Akechi Mitsuhide decide to kill Nobunaga?
Many people assume Mitsuhide rebelled because Nobunaga was preparing for a full-scale war against Mori Terumoto during the campaign in western Japan, and because Honno-ji was poorly defended. However, when you look at the actions of Hashiba Hideyoshi, later known as Toyotomi Hideyoshi, certain details begin to feel suspicious.
There is also the strange fact that Nobunaga’s body was never found, even though he was supposedly killed there. Under normal circumstances, that should have been difficult to explain.
More than 50 theories exist about the truth behind the Honno-ji Incident. All of them are interesting, but no decisive evidence has been found. Still, one of them may contain part of the truth. Below are three theories that seem especially worth considering.
Theory 1: Was It a Plot by Toyotomi Hideyoshi?
One famous theory claims that Toyotomi Hideyoshi planned the incident himself. This idea often appears in fiction.
At the time Mitsuhide attacked Nobunaga, Hideyoshi was marching into the Chugoku region to fight the Mori army. Then urgent news arrived that Nobunaga had been killed. Hideyoshi quickly made peace with the Mori and defeated Mitsuhide at the Battle of Yamazaki on June 13.
The suspicious points are how quickly Hideyoshi made peace with the Mori, and how he later became the ruler of Japan. Because Hideyoshi was known for his intelligence, some believe he may have arranged the incident as part of his path to unifying the country.
Unfortunately, there is no evidence for this theory, so it remains only a hypothesis. However, if it were true, most people involved would likely have been killed, and important documents may have been burned. For that reason, some people feel it cannot be completely dismissed.
Theory 2: Akechi Mitsuhide Acted Alone
This is one of the more widely accepted theories. It suggests that Akechi Mitsuhide killed Nobunaga at Honno-ji either to settle long-held resentment or to rise in power himself.
Nobunaga was an extremely cautious man. Opportunities to kill him were almost nonexistent, and many retainers and enemies had tried to assassinate him before, only to fail. From that perspective, it feels realistic that Mitsuhide saw Honno-ji, a place with few escape routes and weak defenses, as a rare chance.
However, there are still problems with this theory. Mitsuhide failed to recover Nobunaga’s body, and he was unable to unite Nobunaga’s retainers behind him. Before he could secure his position, he was defeated by Hideyoshi. Because of this, no evidence has been found that fully proves Mitsuhide acted entirely on his own.
Theory 3: Was Ashikaga Yoshiaki the Mastermind?
Another theory points to Ashikaga Yoshiaki as the hidden mastermind.
Originally, Mitsuhide had served under Ashikaga Yoshiaki as a shogunate retainer. Yoshiaki had already attempted various schemes to bring down Nobunaga, but those efforts had failed. According to this theory, Yoshiaki sent the talented Mitsuhide into Nobunaga’s circle and waited for a secret chance to strike.
At first, this may sound like pure imagination. However, the person who proposed this theory was a university professor specializing in Japanese history, and he presented several pieces of supporting evidence. Because of that, the theory has a certain level of realism.
The supporting points include:
- Ashikaga Yoshiaki established a shogunate in Okayama and made Mori Terumoto deputy shogun.
- Mitsuhide had been in contact with groups such as the Chosokabe clan and Hongan-ji.
- There was a letter by Mitsuhide referring to Yoshiaki’s restoration to power.
These points, among others, are used to support the theory. If true, it would not be an exaggeration to call Ashikaga Yoshiaki the mastermind.
Even so, there is no perfect proof. Like the other explanations, it remains one theory among many.
For travelers interested in this darker side of Japanese history, sites connected to Nobunaga and the Honno-ji Incident can be fascinating to visit. As always, stick to public areas, follow local rules, and treat temples, memorials, and historic sites with respect.
Japanese Language
第六天魔王として名高い織田信長が、家臣の 明智光秀により討たれた「本能寺の変」 を知らない人は少ないと思います。義務教育を受けていく間に一度は学ぶ内容であり、未だに漫画家やドラマ化もされるほど人気な事変となっています。しかし 本能寺の変は単に明智光秀の裏切りだけでなく、様々な思惑が入り混る謎が多い事変 としても有名なことを知っているでしょうか？。本記事ではそんな 本能寺の変の謎を解く有効な説 などを紹介していきます。公開日：2019年11月8日 更新日：2020年3月15日 。
なぜ謎が多い？。。織田信長といえば横暴な態度や人を容赦なく切り捨てる面があり恐れられていた人物でしたが、同時に圧倒的カリスマ性により多くの家臣に支えられていた人物でもありました。では 。『なぜ明智光秀は織田信長を討つことを決めたのか。』 。ここが本能寺の変において 最大のミステリー となっています。。。多くの人は「中国攻め」で毛利輝元との全面戦争を起こそうとした信長を殺すために明智光秀が「反旗を翻し」守備の薄かった本能寺へ討ち入りをしたと考えていると思いますが、実際は 羽柴秀吉（豊臣秀吉）の対応などをみると疑問に浮かぶ点 もあります。
また 討ち取ったはずなのに信長の遺体が出てきていない などの点もあり、本来であれば見つかっていなければおかしいはずです。50 を超える説がある。。本能寺の変の真相については 50 を超える説があり、どれも興味深い説ではありますが決定的な証拠は見つかっていません。しかし中には正解が隠されているかもしれませんので、個人的に有効だと思える説を紹介します。。豊臣秀吉の策略？。。豊臣秀吉が仕組んだ策略という説は有名でありフィクションでも多く取り上げられている内容となります。
光秀が信長を討ったころ秀吉は毛利軍と戦うために中国地方へ進軍していました。しかし途中で信長が討たれたという急報が入り、急遽毛利と講和を結び 6 月 13 日に山崎の戦いで光秀に大勝を収めています。。ここで注目してほしいのは迅速に毛利との講和を結んだこととその後秀吉は天下人になったことであり、聡明であった 秀吉が天下統一のため仕組んだこと ではないかということです。残念ながらこの説は全く証拠がないため仮説にしかなりませんが実際この説が本当だとしたら関わった人はほとんど殺されていると思いますし、重要な文献も焼き払われていると思うので完全否定はできない説となります。
明智光秀の独断。。これは確信を得ている説ですが、明智光秀が長年抱いていた信長への不満を晴らすためや成り上がるために守備の薄い本能寺で信長を討った説です。信長を確実に討てる機会など「無い」に等しいほど 信長は注意深い男であり、多くの家臣や敵が暗殺などを実行してきましたがことごとく失敗 に終わっています。なので本能寺という逃げ場のない場所にいる状態をチャンスと考えた光秀が思い立って討ち入りしたのではないかという説は現実味があります。しかし肝心な信長の遺体を回収できていないなどの不備があり家臣たちをまとめることができないまま秀吉に討たれてしまっているので、事実を裏付けることができる証拠は出てきていません。
足利義昭が黒幕。。元々光秀は足利義昭の元に仕えていた幕臣であり、足利義昭は信長を討つため様々な策略を実行していましたが失敗している状況にありました。なので優秀な光秀を信長のもとに送り込み密かに討つチャンスを狙わせていた、という説です。「 そんなの空想だ 」と思われる内容ではありますがこの説を唱えた人は日本史を専門とする大学教授で、様々な事実を裏付ける証拠を公表しており、かなり現実味を帯びています。・足利義昭は幕府を岡山に作り毛利輝元を副将軍にしている 。
・光秀は長宗我部や本願寺などと連絡を取っていた 。・義昭の復権を記した光秀の書状があった 。上記が裏付けとなる理由であり（他にもあります）、真実であれば足利義昭が首謀者と言っても過言ではありません。もっとも完璧な証拠はありませんのであくまで数ある説の一部ではありますが
