Honnoji Incident (本能寺の変)

Honnoji Incident is about an event on June 21, 1582 whereby Mitsuhide AKECHI, a key vassal of Nobunaga ODA, rose in revolt and attacked his master, Nobunaga, who had been staying in Honno-ji Temple in Kyoto and Nobunaga committed suicide.

The cause of Mitsuhide's revolt is not clear and, even today, we have no firm explanation about this incident.
There are also many views that there was another ringleader (mastermind), it became one of the big questions in Japanese history. (For more information on individual views, refer to the section on "Fact about the Incident.")

Situation

Up until 1582, Nobunaga had a hold on Kinai (the five provinces in the immediate vicinity of Kyoto) centering around Kyoto and its vicinity and overthrew the Takeda clan in April and May 1582. The Gohojo clan in the Kanto Region and the Date clan in the Tohoku Region signaled their allegiance to Nobunaga and, as a result, enemies that stood in Nobunaga's way were the Mori clan in the Chugoku Region, the Chosokabe clan in the Shikoku Region, the Uesugi clan in the Hokuriku Region and the Shimazu clan in Kyushu.

The Mori clan that for a certain period had harassed Nobunaga by playing a part of an encircling net was forced by Hideyoshi HASHIBA to repeatedly retreat in succession and lost all the influence they had in the past. With respect to the Uesugi clan, after Kenshin UESUGI's death, his adopted son, Kagekatsu UESUGI became the family head and the strong troops that harassed Shingen TAKEDA by fiercely attacking the Kanto Region and Echigo Province had been weakened by the Otate no Ran (Otate disturbance). In Shikoku, Yasunaga MIYOSHI was subject to Nobunaga and, supported by Nagahide NIWA, Nobutaka ODA who had the advantage, had been preparing for war with the Chosokabe clan. In Kyushu, the Otomo clan and the Ryuzoji clan had informed of their intention to obey Nobunaga and, therefore, the Shimazu clan alone was obliged to compete with Nobunaga.

Headquartered in Azuchi-jo Castle, Nobunaga ODA had been promoting unification of the whole country in command of an expeditionary force with commanders such as; Katsuie SHIBATA, Mitsuhide AKECHI, Kazumasu TAKIGAWA, Hideyoshi TOYOTOMI, and Nobutaka ODA and he was forty-nine years old and the situation was such that the whole country would belong to Nobunaga if everything proceeded as planned. Under such situations, as a large military force was dispatched, troops around Nobunaga were not many and Nobunaga and Ieyasu moved around with a small military force in Kinai in an open atmosphere under just before unification of the whole country especially after downfall of the Takeda clan. In this atmosphere, Mitsuhide's troops, which was the de facto Kinki Region Corps of Nobunaga, attacked Nobunaga.

Details

After returning from an expedition to conquer the Takeda clan, on May 15, Mitsuhide served as the marshal to entertain Ieyasu TOKUGAWA who served with distinction in the battles with the Takeda clan for many years. However, Mitsuhide was dismissed midway from the marshal on May 17 and made to return to his residence, Sakamoto-jo Castle, and was ordered to deploy to the front in order to support Hideyoshi. The cause of this dismissal was a request for reinforcements from Hideyoshi HASHIBA that arrived on May 15. On May 26, he moved to another residential castle, Kameyama-jo Castle (Tanba Province) and made preparations for departure to the front. He confined himself in the Atago-jinja Shrine (Kyoto City) for prayer and, on May 28 and 29, he held a party for renga (linked verse) which is very well known from its first line, 'Tokihaima amegashitashiru satsukikana' (The time is now in May, which everybody knows). There is a view that interprets this line as Mitsuhide's determination of revolt (Refer to the section "Other Considerations about Motive and Ringleader"), but there are various interpretations.

On the other hand, on May 29, Nobunaga departed from Azuchi-jo Castle with a small suite, mainly consisting of pages, to the front in order to support Hideyoshi. He entered the Honno-ji Temple in Kyoto on the same day and waited for the assembly of troops. At the same time, Nobunaga's heir, Nobutada ODA entered Myokaku-ji Temple (Kyoto City). Next day, on June 1, Nobunaga held a tea ceremony party in the Honno-ji Temple.

On the same day, June 1 in the evening, Mitsuhide departed the Tanba Kameyama-jo Castle to Kyoto at the head of an army of 13,000 (There is another view that Mitsuhide did not visit Kameyama-jo Castle (Tanba Province) before or after the event and he moved toward Honno-ji Temple from Sakamoto-jo Castle at the head of 3,000 troops and arrived around nine o'clock, that is several hours after seven thirty A.M. when the Honno-ji Temple burnt down.)
The next day, on June 2 before dawn, when they crossed the Katsura-gawa River (Yodo river system), Mitsuhide declared, 'Our enemy is in the Honno-ji Temple,' making it clear that they would attack Nobunaga. According to "Nihon Gaishi" (historical book on Japan) written by Sanyo RAI during the Edo period, it was written that 'We will be reviewed by Nobunaga.' when they departed Kameyama-jo Castle with the intention to attack Nobunaga made clear to all the troops only after they crossed the Katsura-gawa River, but it is a widely-accepted view that, in reality, only a limited number of key vassals were informed of the real intention. There is a view that as the troops numbers were very large, a detached force took another mountain path to Kyoto, Akechigoe, to attack Nobutada. Our enemy is in the Honno-ji Temple' was first seen in "Kawasumi Taikoki" of the beginning of the Edo period, and it was told that the person who participated in the troop of the Akechi clan gave help for "Kawakami Taikoki." According to "Historia de Iapan" by Luis Frois and "Honjo Soemon Oboegaki" (literally, "memorandum of Soemon HONJO") that is reportedly written by a samurai under Mitsuhide who followed the army in the Incident, ashigaru (foot soldier) and low-level samurai in command of them believed at that time that they would attack Ieyasu TOKUGAWA who was staying in the Honno-ji Temple in Kyoto.

Early in the morning (reportedly around four o'clock) on June 2, the troops of the Akechi clan (Mitsuhide had not yet entered Kyoto and he arrived at Honno-ji Temple at nine o'clock; some regard these troops as mysterious as their commander is unknown) completely surrounded Honno-ji Temple.

Nobunaga, who was woke up by sounds, thought that was quarrel of vassals and ordered a kinju (attendant) to check the situation.
Then, he received a report 'The Honno-ji Temple is surrounded by a troop and the crest is kikyo (Chinese bellflower) (Mitsuhide's family crest).'
Nobunaga said, 'We have no other way.' and fought with a bow (weapon) in the front, but as the string of the bow was broken, he took a spear and stabbed enemies. As he got hurt with the spear by rushing enemies, however, he gave up to defend any further and instructed women to run away and, then, he shut himself up in the interior and let his page, Naritoshi MORI, set fire and he himself committed suicide (Writings of Nobunaga's vassal Gyuichi OTA "Shinchoko-ki" (Biography of Nobunaga ODA); it is written that this story based on hearing from such women.). Nobunaga's body was not found.

According to Amidaji (Kamidachiuriomiya) Engi (the history of the Amida-ji Temple), of which temple Nobunaga was a believer, the chief priest, Seigyoku, sneaked in through the hedge in the back of the temple and carried out the body and burnt it. Because of this relation, the 'mausoleum of Nobunaga ODA' in fact exists in the Amida-ji Temple (moved to Tsuruyamacho, Kamigyo Ward). As the Honno-ji Temple was surrounded with moats walls and mud walls, this story is doubtful.

In addition, as it is also told with respect to this history book, 'Nobunagako Amidaji Yuishono Kiroku,' that because the old records were burnt, it was reconstructed in 1731 based on memory, this book is unbelievable including the story that Nobunaga, who did not believe Buddhism, was the believer of this temple. With respect to the reason why Nobunaga's body was not found, there is a view that it was impossible with capability of search at that time to find the in large volume of wreck after a huge building was burnt down.

According to "Historia de Iapan" by Luis Frois whose church was only 200 meter away from the Honno-ji Temple, '(Around three o'clock in the morning), (a small number of) warriors of the Akechi clan invaded the temple without being suspected (It seems that Oda's gatekeepers lost their sharpness because they knew that umazoroe (a troop review) in front of the Imperial Palace was planned for the next day.), and shot Nobunaga, who came out from the toilet and was washing his hands and face, in the back using bows and arrows. Immediately after that, Nobunaga called his pages and counterattacked warriors of the Akechi clan brandishing a sickle-like weapon (naginata (Japanese halberd) art), but he was shot his left shoulder by a bullet shot by the musket troops of the Akechi clan.
Immediately after that, he closed the shoji (sliding paper door) (and set fire and committed suicide).'

Nobutada, who received a report of the revolt by the Akechi clan, intended to go to the Honno-ji Temple to rescue, but he was dissuaded by his close aide to run away because the situations in the Honno-ji Temple were already finalized. However, Nobutada judged that Mitsuhide's troop must have surrounded and were executing inspection and gave up to run away and left the Myokaku-ji Temple which was not suitable for defense. In reality, however, as encirclement was not sufficient and, for example, Nagamasu ODA succeeded to escape, Nobutada's judgment was a big mistake that could change the history. Thus, Nobutada moved to Nijo Gosho (newly built Imperial Palace in Nijo) together with Sadakatsu MURAI who was responsible for administration of Kyoto. Nobutada fought as a brave commander and cut two warriors down despite many wounds and showed fierce resistance and drove Mitsuhide's troop retreat three times. As time passes, umamawari (guard) who were staying in different places in Kyoto came one by one, and the success of the revolt became doubtful. As a last resort, Mitsuhide's troop shot the Nijo Gosho with guns and bows and arrows from the roof of neighboring Sakihisa KONOE's mansion from which they could see the inside of the Nijo Gosho very well and killed almost all of attendants. Thus, Nobutada committed suicide by sword and the Nijo Gosho (Nijo Imperial Palace) fell.
("Shinchoko-ki" (biography of Nobunaga ODA); "Todaiki" (a historical record))

Together with Nobutada, Nagamasu ODA (later, Urakusai ODA) who was Nobunaga's younger brother, also stayed in the Myokaku-ji Temple and he moved to the Nijo Gosho together with Nobutada and he run away before the fall of the castle. ("Mikawa Monogatari")
He fled to Gifu Prefecture through the Azuchi-jo Castle and he was safe.
As Nagamasu did not commit suicide and fled while Nobutada committed suicide, it is told that people in Kyoto ironically commented 'Gengo ODA is not a human being. He let Nobutada commit hara-kiri and he himself fled to Azuchi. On June 2, the flooding and the name of the origin of Oda was washed out.'

It is told that, when Nobutada fought bravely in the Nijo Gosho, his vassal Yasuke, who was a negroid also fought. Originally, Yasuke was a negroid slave who was presented to Nobunaga upon his request at the occasion of giving audience to a missionary. Yasuke was captured after this battle and he was not killed, but he was never heard from again. In dramas in which the Honnoji Incident is mentioned, it is often described that Yasuke died in battle following his master, Nobunaga.

By the way, in 2007, excavation and research of the ruin of the Honno-ji Temple was conducted and traces of moat and bank protection were found together with a large volume of burnt roof tiles of the same period as the Honnoji Incident. It proved that, as mentioned in historical materials, the Honno-ji Temple was remodeled as the accommodation for Nobunaga in February and March 1580 by constructing moats and mud walls and newly building a stable and reconstructing the main building. It also showed that the Nobunaga noticed the Honnoji Incident and prepared armaments in the Honno-ji Temple against the enemy forces.

Cause of the Incident

Partly because of dramas, many persons understand that the cause of the incident was repeated harassment by Nobunaga, but it is just a fiction without any ground. Also, many persons understand that it was a coup d'état or a reaction (antirevolutionary act -revolution) against Nobunaga's radical behavior to change traditional society of Japan (such as oppression of Buddhism).

With respect to Mitsuhide's motive for raising an army, there are various views such as resentment, ambition to conquer the whole country and protection of the imperial court and no consensus has been formed.

View that cause was resentment

The generally-known views that the cause of the incident was resentment are as follows:

He served ill-smelling fish and lost his face by being dismissed from the position of marshal for Ieyasu. Then, Mitsuhide was chagrined and threw plates and utensils into the pond ("Kawasumi Taikoki").

He was ordered transference of his fief to Izumo Province, Hoki Province or Iwami Province which was still enemy territory ("Ehon Taikoki"). With respect to the Battle of the Yagami-jo Castle, Nobunaga caused death of Mitsuhide's mother ("Ehon Taikoki"). In the victory celebration for the battle in which the Takeda clan was destructed, Mitsuhide told, 'It makes all our efforts worthwhile.' and Nobunaga questioned what Mitsuhide said and hit and kicked Mitsuhide saying 'What you did for this result!' and Mitsuhide resented this ("Sofu Monogatari").

Those stories were kodan (story-telling) created in the Edo period and later and there was no reliable backup data.

With respect to the 'view that the cause of the incident was transference of the fief,' as only one historical material, there is Nobutaka ODA's military order dated May 14, nineteen days before the Incident, that imposed military service on local lords and powerful local clans in Tanba, and it became the subject of academic arguments whether or not kao (written seal mark) on this military order is genuine. However, as similar transference of the fief to enemy's territory was carried out for Hiromasa YANADA and Kazumasu TAKIGAWA and their former fiefs were guaranteed for a certain time period, there is a view that it was a custom at that time to guarantee the former fief until the new fief is in fact acquired.

Independently from these, it is recorded in "Historia de Iapan" of Luis Frois that, several months before the incident, there was such quarrel as Mitsuhide said something and then Nobunaga shouted and Mitsuhide immediately came out the room and returned to his place.

In Mitsuhide's writings "Akechi-kaho" (family rules of the Akechi clan) written one year before the incident, Mitsuhide wrote a sentence that reads "I was set up in the world by Nobunaga from the status like a pebble and I owe him a lot. My family and vassals including their descendents should not forget to serve to Nobunaga." Judging from the sentence, we can surmise that Mitsuhide had adoration and respect toward Nobunaga. It seems that Mitsuhide had high regard for Nobunaga as we see in the fact that he hung Nobunaga's handwriting in the alcove in which a treasure should be placed for the tea ceremony held three months before the incident. Therefore, views that adopt other motive than resentment have also been supported and, especially, views that assume existence of a mastermind is strong.

In "Historia de Iapan" by Luis Frois, we can find many comments on Mitsuhide, such as 'He likes treachery and clandestine meeting.,' 'He is cruel in imposing a punishment.,' 'He is patient.,' 'He is a master with trick and stratagem.,' 'He is good at building castles.,' and 'He knows how to use skilled samurai.'
Traditionally, Mitsuhide has an image of sincere person most probably because of dramas or the fact that in certain areas including Tanba Province which was Mitsuhide's fief, people recall beneficial influence of Mitsuhide. Separately from the image of Mitsuhide that he was a highly cultured but feeble looking, we can see an aspect of Mitsuhide as a tough busho (Japanese military commander) in the Sengoku Period as commented by Frois and praised by Nobunaga in 'Sakuma Nobumori sekkanjo' (letter to reproach Nobumori SAKUMA).

View which advocates that Incident was to avoid conquest of Shikoku

This view surmises that the cause of the Honnoji Incident was to avoid conquest of Shikoku planned by Nobunaga.

In Shikoku, Motochika CHOSOKABE of Tosa Province made relation by marriage with a vassal of the Akechi family, Toshimitsu SAITO, and had been making effort to unify Shikoku under amicable relation with Nobunaga through Mitsuhide. On the other hand, defeated Yasunaga MIYOSHI in Awa Province aimed at recovery of this former territory by making arrangement for alliance with Hideyoshi (He adopted a Hideyoshi's nephew, Hidetsugu TOYOTOMI). As Nobunaga did not want to have Shikoku unified by the Chosokabe clan, he ordered Motochika in March and April 1582 to govern only two Provinces, Tosa and Awa, and visit Kyoto. As Motochika refused this order, it is decided to conduct conquest of Shikoku with Nobutaka ODA (the third son of Nobunaga; it had been informally decided that, after conquest of Shikoku, he should be adopted by the Miyoshi clan and succeed the Miyoshi family.) as the chief commander.

It had been planned that, at first, Yasunaga would enter Shikoku as a spearhead and, on July 1, the main body of troops led by Nobutaka, Nagahide NIWA, etc. would start from Osaka to go into battle.

This view was insisted by Mitsutoshi TAKAYANAGI etc. immediately after the War and Takayanagi and his supporters have been advocating for a long time.
Probably as self-recrimination against the view that the imperial court was the mastermind of this revolt, Sakujin KIRINO advocated, 'Nobunaga needed the Chosokabe clan in order to contain the navy of the Mori clan, but because of deportation of Honganji and decline of the navy of the Mori clan made the Chosokabe clan needless for Nobunaga. As a result, the position of Mitsuhide and Toshimitsu, who made best effort to establish the relation of relative and matrimonial relation with the Chosokabe clan became undermined.'
Based on such point of view, he published "Shinsetsu Honnoji" (new view on the Honnoji Incident) in 2001 and "Darega Nobunaga wo Koroshitanoka Honnoji no Hen - Aratana Shiten" (Who killed Nobunaga - Honnoji Incident/new point of view) in 2007.

View that there was a mastermind

There are several views which advocate that the motive for killing Nobunaga was not Mitsuhide's own, but a certain mastermind whose intention caused the incident existed, as described below.

View which advocates that mastermind was Yoshiaki ASHIKAGA

This view advocates that Yoshiaki ASHIKAGA who had hard feelings against Nobunaga who had expelled him and ruined the Muromachi bakufu (Japanese feudal government headed by a shogun), tempted Mitsuhide in order to regain Yoshiaki's power. This view has been advocated centering around Professor Tatsuo FUJITA of the Mie University.

The Imperial Court sensed a threat from Nobunaga who had been increasing his power day by day and, in order to measure Nobunaga's loyalty to the Imperial Court, sent in 1582 a letter from the Imperial Prince Sanehito that read 'You may have any official position that you wish to have.' to Nobunaga (Sanehito Shinno Goshosoku (letters of the Imperial Prince Sanehito)). However, Nobunaga let the imperial envoy, who delivered the letter, go back without giving clear reply.

The Imperial Court was flustered by Nobunaga's attitude to pay little attention to the emperor, and Yoshiaki ASHIKAGA was afraid that Nobunaga might ask the imperial court for appointment as Seii Taishogun (literally, "great general who subdues the barbarians") and proposed Mitsuhide AKECHI, who had once been Yoshiaki's vassal, to assassinate Nobunaga. It is told that Mitsuhide, who had been moved to a sinecure by Nobunaga, accepted this proposal and made a plan for Honnoji Incident.

Fujita advocated that Yoshiaki ASHIKAGA existed in the background of Mitsuhide pointing out that, as evidences to substantiate his view, Mitsuhide's envoy who was sent to Kagekatsu UESUGI immediately before Honnoji Incident asking for cooperation stated 'The Uesugi should cooperate' ('Kakujokogoshoshu') requesting cooperation to a person who was in higher position than Uesugi's. In addition, Mitsuhide sent a letter to Shigeharu TSUCHIBASHI, who was a member of the Saigashu (a powerful local clan in Saiga, Kishu), saying, 'A joi (order from a superior to a subordinate) has been issued requesting that you provide service, which is a great honor', and Fujita pointed out that as the word 'joi' was used, the order must be from someone with a higher status than Mitsuhide.

Grounds for this view are the connection between Mitsuhide and Yoshiaki before Mitsuhide became a vassal of Nobunaga and Yoshiaki's past action proposing a coalition of various daimyo (Japanese feudal loads) to overthrow Nobunaga. Against this view, there is a refutation which advocates that it is impossible to reason why the Mori clan, which had been protecting Yoshiaki, did not know about Honnoji Incident (according to accepted view). The ground for this refutation is the idea that if Yoshiaki was the mastermind, the Mori clan should have known it.

With respect to this refutation, there is a heresy regarding whether or not the Mori clan knew about Honnoji Incident. In Taikoki and Sakuma Gunki, it is described that the Mori clan already knew about the occurrence of Honnoji Incident at the time of negotiations for peace, and Takakage KOBAYAKAWA proposed 'Because Hideyoshi will govern the country after Nobunaga, we should put Hideyoshi under an obligation at this stage.' supporting negotiations for peace. If this is the fact, it does not contradict the view that the mastermind was Yoshiaki. Also, some considers that, even Shigeharu TSUCHIHASHI, who was a mere dogo in Saiga, Kishu, offered Mitsuhide cooperation to overthrow Nobunaga, it is not strange that the Mori clan knew above Honnoji Incident.

View which advocates that the mastermind was the imperial court

Among views which advocates that the mastermind was the imperial court, there are different views with respect to the key person of the plot, for example, the Emperor Ogimachi, Imperial Prince Sanehito or a noble such as Sakihisa KONOE.

One of grounds for this view is that the imperial court might consider that Nobunaga had an intention to overthrow the imperial court surmising from Nobunaga's response with respect to 'sanshokusuininnmonndai' (matters related to the Imperial Court's offer to Nobunaga to appoint him to Semi Daishogun, Daijo Daijin, or Kanpaku according to Nobunaga's wish). After killing Nobunaga and Nobutada, Mitsuhide visited the Imperial Court and he was granted Imperial gifts of money and other valuable goods. Other grounds that support the views that the mastermind of the plot was the Imperial Court are that, after the Battle of Yamazaki, Nobutaka ODA tenaciously searched for Sakihisa KONOE by issuing an order to track down and dispose of him, that Kanemi YOSHIDA was interrogated for information, and that the original contents of "Kanemikyo-ki" (diary of Kanemi), which is the first class historical material for that time, were missing for approximately one month around Honnoji Incident and the section for 1582 was rewritten.

The facts that 'sanshokusuininmondai' occurred immediately before Honnoji Incident and from its nature, it was not a matter for which Nobunaga could answer instantly and it seems that the purpose of making stopover at Kyoto was to give his answer raise a doubt with respect to the above-described grounds (It is possible to interpret that Mitsuhide attacked the Honno-ji Temple in order to prevent Nobunaga from giving an answer).

It has been also pointed out as refutations that Sakihisa KONOE became a priest on the day of or several days after Honnoji Incident and it seems appropriate to understand his becoming a priest was to follow Nobunaga same as Yusai HOSOKAWA's becoming a priest and that Sakihisa KONOE made a waka (31-syllable Japanese poem) which mourned Nobunaga's death. With respect to search by Nobutaka, there is a view which considers that it was just to blame Sakihisa for having allowed Mitsuhide's army to climb on the roof to attack and kill Nobutada. With respect to the Emperor Ogimachi and the Imperial Prince Sanehito, no reliable evidence exists and these views are no better than supposition. With respect to the Imperial Prince Sanehito, especially, the fact that he could be entangled in an incident in the Nijo Gosho is mentioned as a refutation against the view that the mastermind of the plot was in the Imperial Court.

If the emperor or the Imperial Court was involved in the plot, why Mitsuhide was not justified by a rinji (message from an emperor) or donation of a sword?
In this case, the emperor or the Imperial Court is not accused later.
Why Mitsuhide did not announce his relation with the Imperial Court or the emperor?
Recently, in many studies, it is mentioned that Mitsuhide has no merit to ally with the Imperial Court in that way.

In 2007, Sakujin KIRINO, who published in 1992 "Nobunaga Bosatsu no Nazo" (mystery of deliberate murder of Nobunaga) based on "Kanemikyo-ki," criticized his own view by admitting in an interview with a researcher that he was told by a researcher "This is a kind of inboshikan (conspiratorial interpretation of history)." and that 'at that time, he could hardly read writing in simplified style in ancient documents.'

Whether or not involvement of the Imperial Court in the plot is denied, views on the relation between Nobunaga and the Emperor Ogimachi are divided into two groups, one to look at the point that Nobunaga is said that he required abdication and the other to look at the fact that the Emperor Ogimachi himself wanted to abdicate but Nobunaga did not agree. In many cases, the former group refer to a description in "Takachika Nikki" (Takachika NAKAYAMA's Diary) of January 10, 1574 and the latter a description in "Kanemikyoki" of May 13, 1581, it is observed that they tend to pick up a part of Nobunaga's policy with respect to the Imperial Court that had changed over time to use as the ground for their own view.

With respect to calendar, an error, which contradicted the rule of the lunisolar calendar had occurred in the Kyo calendar (calendar prepared by the onmyoryo (governmental agency responsible for matters related to the Way of Yin and Yang)), that usui was not included in January 1581 but shifted to the intercalary first month in which chuki should not be included. According to description for June 1, 1580 (old calendar) in 'Nichinichiki' of Harutoyo KAJUJI, who was a noble and Buke Denso (imperial official in charge of communication with the shogunate), Nobunaga officially pointed out this problem even one day before his death. Here also, there is a dispute whether it should be interpreted as one of Nobunaga's campaigns to show his superiority or expression of Nobunaga's loyalty to the Imperial Court.

Based on the description about deification of Nobunaga in 'Historia de Iapan' by Frois, there is a view which points out that deification of Nobunaga could not be accepted by the Imperial Court. (Motohiko IZAWA is the recent advocator of this view.)
However, because of reliability of descriptions by Frois, rather many views overlook or neglect it.
(Refer to "Other consideraitons about motive and ringleader.")

Regardless of difference between those views, there is hardly any dispute on the fact that Nobunaga who became the largest bearer of the finance of the Imperial Court was in a position to intervene the decision making of the Imperial Court and therefore there was a conflict between Nobunaga and the Imperial Courts and the difference between the views depends on which element of Nobunaga's act and intervention and how they evaluate it.

In 'Nichinichiki' of Harutoyo KAJUJI, there is a description which hints that there was a plot (discussion) 'to overthrow Nobunaga' between Mitsuhide and persons form the Imperial Court as follows:June 17 (old calendar) FineIn early morning, Kuranosuke SAITO, who belonged to the Akechi clan and discussed about overthrowing Nobunaga, was caught and paraded through Kyoto.

View which advocates that mastermind was the society of Jesus

This view was advocated by Kyoko TACHIBANA assuming that the Society of Jesus intended to realize political power change in Japan. In this view, 'Nobunaga's government itself was just a puppet government of the power from the southern Europe. It is told that Sorin OTOMO was the mediator between the Society of Jesus and Nobunaga and the final purpose of the Society of Jesus was to conquer Ming by force and, in short, the purpose of the Honnoji Incident was just to switch from Nobunaga to Hideyoshi. As a refutation against this view on the point that 'Nobunaga had been receiving funds from the Society of Jesus,' it is pointed out that the constant income of the Society at that time was around 20,000 cruzados and that more than a half of it had been remitted to India and, therefore, the Society did not have sufficient fund for maintenance and operation. In addition, the writing of Katsuhiro TANIGUCHI in 2007 raised a question about TACHIBANA's way of handling historical materials such as quoting many unreliable materials of the Edo period such as "Akechi Gunki" (biography of Mitsuhide AKECHI) without verification.

View that the mastermind was Hideyoshi HASHIBA

As Hideyoshi obtained information on Nobunaga's death very quickly and he had not lost his military power by enveloping attack of the Takamatsu-jo Castle in Bicchu Province, it is said that he must have known about the Honnoji Incident in advance. It is also because Hideyoshi fought with Mitsuhide under very favorable condition and won the battle and he became a tenkabito (a person who holds the reins of government) taking advantage of Honnoji Incident and as a result, obtained the largest advantage.
We cannot say that this view has well accepted as a theory because it lacks concrete evidence, but this view has often been adopted in fictions, etc. in accordance with the theory for reasoning 'Doubt the person who obtained the largest advantage.'

Refer to the view that Hideyoshi TOYOTOMI was the mastermind of Honnnoji Incident.

View that mastermind was Ieyasu TOKUGAWA

The views that Ieyasu TOKUGAWA was the mastermind of the plot are supported only by many circumstance evidences, but their contents are made interesting by the view that Tenkai Sojo (high rank Buddhism priest) (Nankobo) was Mitsuhide. Such views do no advocate that Ieyasu was the ringleader, but he agreed or supported the plot and, after the event, sheltered Mitsuhide, who had lived as a priest. This story has been often referred to in historical novels.

According to 'Historia de Iapan' by Frois, when Ieyasu visited Nobunaga on June 15, 1582, immediately before the Incident in Azuchi-jo Castle accompanied by Nobukimi (Baisetsu) ANAYAMA, who was a surrendered warlord from the Takeda clan to celebrate the victory in the battle Mitsuhide was at first appointed to the position of marshal. With respect to preparation for those events (entertainment for Ieyasu), Nobunaga was talking with Mitsuhide behind closed doors, but because Nobunaga tended to go wild with rage by nature and could not accept that someone oppose to his order, he chastised Mitsuhide and dismissed Mitsuhide from the position of marshal.

In this regard, many views infer that Nobunaga had an intention to assassinate Ieyasu, for example, assuming that the reason why Nobunaga got angry was not mismanagement of entertaining such as 'rotten fish' in 'Taikoki,' but the real cause was that when Nobunaga ordered Mitsuhide to kill Ieyasu taking opportunity of entertainment but Mitsuhide refused this order.

As descriptions in historical books that support this view, it is well-known that a section of 'Historia de Iapan' by Frois continued as, when Mitsuhide reversed the course to Kyoto, 'Soldiers began to wonder about the purpose of such action (to attack the Honno-ji Temple and thought that Mitsuhide intended to kill the lord of Mikawa Province (Ieyasu), who was a younger brother-in-law of Nobunaga, according to Nobunaga's order, and a section of 'Rojinzatsuwa' by Munetomo EMURA.'
Also, a well-known quotation from "Rojinzatsuwa" (literally, miscellaneous stories by an old man) by Munetomo EMURA states: "On the occasion of the Akechi Disturbance (Honnoji Incident), Toshogu (Ieyasu) was in Sakai. Nobunaga ordered Togoro HASHIBA to act as a sightseeing guide for Ieyasu in Osaka and Sakai, but in reality, it was a plot to exploit an opportunity to kill Ieyasu".

In addition, following points have been advocated together with the above-described views.

As seen in the case of the order to kill Tsukiyama-dono, who was Ieyasu's legitimate wife, and Nobuyasu MATSUDAIRA, who was Ieyasu's first son, Oda and Tokugawa were not in a relationship of equality like 'allied countries' as often been idealized later, and, for Oda, Tokugawa was a mere throwaway player and, in order to pacify the eastern countries, it should be completely weakened or overthrown as soon as possible.

Although it was told later that Ieyasu's runaway trip guarded by Iga ninja (a secret agent (in feudal Japan) highly skilled in stealth and secrecy), who were opponents to Nobunaga was because of Ieyasu's fear against to be killed by the Mitsuhide's side, it was originally prepared in advance based on Ieyasu's fear against being killed by the Nobunaga's side or it was an arrangement to deny his participation in the plot.

With respect to views that Tenkai Sojo (Nankobo) was Mitsuhide who lived after Honnoji Incident, there are many views that point out the following facts and look at Ieyasu's acts that have been accepted as appraisal to Mitsuhide.

The head which was shown as Mitsuhide's were inspected in considerably decomposed condition.

The first half of Tenkai Sojo's life is not known. However, he was very capable so that he joined the war council and Ieyasu relied on. Evidently, he was not a usual priest.

In Mt. Hiei, there is a stone lantern which is inscribed that 'Petitioner: Mitsuhide' donated it in February and March 1615.

The painted image of Mitsuhide that remained in the Hontoku-ji Temple in Osaka, which temple looks after Buddhist memorial tablet of Mitsuhide, has a comment that reads '放下般舟三昧去' on its back and, literally, this comment means that Mitsuhide spent his remaining years in Buddhist priesthood.

Kasuga no Tsubone, who was a daughter of Toshimitsu SAITO, showed the highest politeness by 'prostrating herself' before Tenkai, with whom she must met for the first time, and stated, 'It is a long time since we met each other last time.'

Crests on the wooden figure of samurai in Yomeimon (Yomei gate) and the belfry of Toshogu Shrine are 'Chinese bellflower' that was the family crest of Akechi.

Although the reason is not known, Ieyasu had a kumage no yari (spear decorated with hairs of bear) that once belonged to Mitsuhide and gave it to his cousin, Katsunari MIZUNO telling 'This is a spear that was once owned by Hyuganokami, who was a famous general. Have similar military achievements to Hyuganokami's.'

If we put together '光' (mitsu) in Iemitsu and '秀' (hide) in Hidetada, we have '光秀' (Mitsuhide). (However, the character 秀 (hide) in Hidetada was given by Hideyoshi from his name same as in Hideyasu MATSUDAIRA.

Views which point out other masterminds

Views that the mastermind was a wealthy merchant in Sakai (Sen no Rikyu)

Views that mastermind was Terumoto MORI (or Takakage KOBAYAKAWA)

Views that conspiracy of the Imperial Court and Hideyoshi HASHIBA

View that the Shimazu clan was involved - It was a matter of time when Nobunaga commence conquering Kyushu after he overthrew the Mori clan. View that the Shimazu clan, that had been in a predicament because of counteroffensive activities by the Otomo clan and the Ryuzoji clan connected with Nobunaga, plotted with nobles in the Imperial Court. Although there was little grounds, in description in 'Uwai Kakuken Nikki' that is famous as the diary of Uwai Kakuken, who was a close vassal of Yoshihisa SHIMAZU, sections for the period from July 1, 1582, when Honnoji Incident occurred, to November 28 were left blank. The question why those sections were not touched remains.

Other considerations about motive and ringleader

Although it is not clear since when Mitsuhide made his mind to rebel, there is a view that he made his mind to rebel at the time of the party for renga (linked-verse) in the Atago-gongen Shrine before going to battle from the Kameyama-jo Castle by understanding the first line made by Mitsuhide, 'Tokihaima amegashitashiru satsukikana' (The time is now in May which everybody knows), as 'toki' means Mitsuhide himself, who belonged to the Toki clan which descended from the Minamoto clan and 'amegashitashiru' as 'to govern the area under the heaven,' namely governing the whole country.
* There is another view that Mitsuhide meant 'Time is now May and all are in rain.'

According to 'Historia de Iapan' by Frois, Nobunaga held a ceremony on June 15, 1579, in the Azuchi-jo Castle to make himself a god and decided in the Soken-ji Temple to make his birthday a holiday and told that those who visit and worship would have benefit in this world. However, as Frois first written about this 'ceremony' only after Nobunaga's death and he was not in the vicinity of Azuchi when such ceremony was held and this 'ceremony' has never been referred to in first-class historical materials in Japan, Katsuhiro TANIGUCHI proposed the view that description by Frois is not reliable and it was written just to justify overthrowing Nobunaga.

Mitsuhide AKECHI

After spending July 6 and 7, 1579 for calling on other warlords to surrender, Mitsuhide entered the Azuchi-jo Castle on July 8 (There is a view that he entered the Azuchi-jo Castle on July 7). On July 12, he went up to Kyoto and commenced political maneuvering toward the Imperial Court, but having received a report on Hideyoshi's ogaeshi (long distance return in short time) took the field to Yamazaki. He was defeated in the Battle of Yamazaki on July 16, and, in the midnight on the same day, killed by a native in Ogurusu (Fushimi Ward, Kyoto City). As he administered political affairs in Azuchi and Kyoto from July 7 or 8 to 15, it was called mikkatenka (a very brief reign; literally, three-day reign).

It can be said that one of causes of his defeat was that he did not have sufficient military strength caused by his failure to acquire support from powerful warlord in the Kinki area such as Yusai HOSOKAWA, who was his relative, and Junkei TSUTSUI, who was a yoriki (warlord attached to another) to Mitsuhide.

Hideyoshi HASHIBA

Hideyoshi had been confronting with the Mori clan, while his troop had been enveloping the Takamatsu-jo Castle in Bicchu Province in which Muneharu SHIMIZU holed up.

He received a report on Nobunaga's untimely death as early as on July 6, he concluded peace with the Mori clan quickly. Seeing that the troop of the Mori clan left on July 9, he turned back his troop and, on July 15, already arrived in Settsu Province. He won Kiyohide NAKAGAWA, Ukon TAKAYAMA and Tsuneoki IKEDA, who were warlords in Settsu Province to his side here, and merged with Nobutaka ODA and Nagahide NIWA, who were in Sakai City for dispatching troops to Shikoku. He marched to Kyoto leading those troops and he defeated Mitsuhide in the Battle of Tennozan on July 16. This movement from the Chugoku area in a very short period is called Chugoku ogaeshi.

Hideyoshi, who aimed to take the initiative in the Oda government, became the guardian for Sanposhi (Hidenobu ODA), who was a son of Nobutada, as a result of the Meeting in Kiyosu-jo Castle and established his position as the successor of Nobunaga.

Katsuie SHIBATA

On July 6, after attacking the Uozu-jo Castle in Ecchu Province for three months in cooperation with Narimasa SASSA and Toshiie MAEDA, Katsuie succeeded to overrun it. However, Nobunaga did no exist at that time. After the news of the incident arrive, he could not quickly return his troop to Kyoto like Hideyoshi because of counterattack by Kagekatsu UESUGI and uprising of local samurai. When Katsuie arrived Kohoku at last, Mitsuhide AKECHI had already been killed. Later, he confronted with Hideyoshi in the Kiyosu conference and was defeated in the Battle of Shizugatake and committed suicide.

Ieyasu TOKUGAWA

After having visited the Azuchi-jo Castle at Nobunaga's invitation in June, Ieyasu stayed in Sakai together with over thirty vassals. In the morning of July 5, when he was traveling Nagao kaido (Nagao road) heading to Kyoto to make a return call, he met Shirojiro CHAYA, who hastened from Kyoto, in the vicinity of Shijo Nawate and knew about Honnoji Incident. Ieyasu got flustered and said that he would go to Kyoto and follow Nobunaga to the grave in Honno-ji Temple, but he was convinced by his vassals and tried to go back to his territory. He passed through Tsuzuki in Yamashiro Province, Kabuto Pass in Omi Province and mountains in Iga Province to Ise Province and went across Ise-wan Bay and returned to his territory, Mikawa Province.

This was the biggest crisis for Ieyasu as called 'shinkun no gokannan' (big trouble for Ieyasu TOKUGAWA) later. In fact, according to "Mikawa Monogatari," the group of Nobukimi ANAYAMA, who accompanied Ieyasu but kept a certain distance because he had a considerable amount of money and goods and was afraid of being robbed of them by Ieyasu's valets was caught up and killed by natives who were looking for fleeing defeated warriors at the ferry on the bank of the present Kizu River (in the vicinity of the present Yamashiro-Ohashi in Kyotanabe City, Kyoto Province) in Tsuzuki County, Yamashiro Province. Ieyasu could escape with very slight difference. On this occasion, the Iga lineage cooperated with Ieyasu for getting across Iga and, because of the merit of Hanzo HATTORI, who was the head of Iga at that time, 'Hanzomon' (Hanzo gate) was constructed in Edo-jo Castle. However, there is a legend that Ieyasu was killed in Sakai and, in Nanshu-ji Temple in Sakai City, there exists a tombstone inscribed with his name, but this is a legend created later at the time of Osaka no Eki (the siege of Osaka).

After coming back to Mikawa Province, he departed to kill Mitsuhide, but when he arrived at the Atsuta-jingu Shrine, he heard about the Battle of Yamazaki and went back. According to a certain view, Tadatsugu SAKAI had already marched up to Northern Ise. If this is true, Ieyasu must have divided his troop into two, one to march to Kyoto through Mino and the other to march to Kyoto through Ise.

After that, Ieyasu occupied Shinano Province and Kai Province, which became vacant because of Nobunaga's death and became a very big daimyo (feudal load) surpassing the Takeda family in their height of prosperity.

Nobukatsu ODA

After Honnoji Incident, Nobukatsu ODA, who was the second son of Nobunaga, marched to Tsuchiyama, Omi Province, to attack Mitsuhide, but he retreated because Mitsuhide was badly defeated by Hideyoshi in the Battle of Yamazaki. Nobukatsu was not nominated in the Kiyosu conference to the heir of the Oda family (It was partly because that he had been adopted by the other family, but the fact he had repeatedly committed mistakes was also a important factor.). As he was not satisfied with this and opposed to Hideyoshi in cooperation with Ieyasu for a certain time, but, finally made peace and surrendered to Hideyoshi (the Battle of Komaki-Nagakute).

Kazumasu TAKIGAWA

Kazumasu was in the Umayabashi-jo Castle in Kozuke Province. Although he retreated as soon as he heard the report on Honnoji Incident, Ujinao HOJO in Odawara City marched aiming at to take Kozuke Province and Kazumasu tried to break through the enemy lines and badly defeated and came back to his territory, Ise Nagashima-jo Castle (the Battle of Kanna-gawa River). Because of defeat of Kazumasu, the influence of ODA in Kozuke Province and Shinano Province was swept away and Kazumasu was removed from the group of chief vassals and he could not attend the Kiyosu conference.

Nobutaka ODA/Nagahide NIWA

Nobutaka was making preparation for conquest of Motochika CHOSOKABE of Shikoku in cooperation with Nagahide, Nobusumi TSUDA, who was a Nobunaga's nephew (his father was Nobuyuki ODA) in Osaka. As soon as information on Honnoji Incident was conveyed, Nagahide NIWA immediately killed Nobusumi following Nobutaka's order. Then, Nagahide NIWA, together with Nobutaka, merged with the troop of Hashiba heading to Kyoto.

Nobusumi was killed because he deemed to have a connection with Mitsuhide since his father, Nobukatsu had a plot to rebel against Nobunaga and he was killed and he was a son-in-law of Mitsuhide.
However, there is a view that advocates 'Nobutaka, who knew that not only his father, Nobunaga, but also his elder brother, Nobutada, were killed, killed Nobusumi who might become a candidate for the family head of the Oda clan, by making a false charge.'

Motochika CHOSOKABE

Partly because of influence of Conquest of Shikoku by Nobunaga, Motochika CHOSOKABE was giving a rest to his warriors in the Hakuchi-jo Castle. As soon as he knew about Nobunaga's death, however, he dispatched troop and won the Battle of Nakatomi River and took complete control of Awa Province and Sanuki Province.