The Meiō incident, or Meiō coup (Japanese: 明応の政変, Hepburn: meiō no seihen), was a late 15th century coup d'état in Japan, when deputy-shogun Hosokawa Masamoto deposed the tenth shogun of Japan, Ashikaga Yoshitane. On the night of 9 May, 1493, Masamoto raised troops in Kyoto. With support from Hino Tomiko and Ise Sadamune, he deposed Yoshitane (at the time Yoshiki), installing Ashikaga Yoshizumi (at the time Yoshitō) as the new shogun. Although the coup was initially successful, Yoshitane escaped from house arrest in Kyoto and established himself in Etchū Province. Masamoto failed to decisively defeat him again, effectively splitting Japan between two rival governments. Masamoto also faced internal opposition from the Awa branch of the Hosokawa clan, especially after he adopted an heir from outside the clan. In 1507, Masamoto was assassinated, and Yoshiki deposed Yoshitō the following year.
The primary cause of the Meiō incident was that Yoshitane continued fighting military campaigns despite Masamoto's objections, particularly his campaign against Hatakeyama Yoshitoyo in Kawachi Province. The aim of the campaign was the reunification of the Hatakeyama clan under Hatakeyama Masanaga, which Masamoto opposed because the Hatakeyama clan was the most powerful rival to the Hosokawa clan for the position of kanrei. In addition, Yoshiki had begun to rely more on other daimyo, including Masamoto's rival Hosokawa Yoshiharu, with the intention of reducing his dependency on Masamoto.
The coup and the subsequent conflict heavily reduced the shogunate's power over the daimyo, as it was forced to rely on the support of powerful clans. The Hosokawa clan was divided into two warring factions after Masamoto's death, while the Ōuchi clan under Ōuchi Yoshioki reached the height of its influence. In addition, the shōgun-ke (将軍家; family members of the shogun who could succeed him) was subsequently divided into those descended from Yoshitō and those descended from Yoshiki.
Background
In the Ōnin War, Yoshiki supported his father Ashikaga Yoshimi, who was the commander of the Western Army. After the conflict, the Western Army was weakened, and the pair took refuge with Toki Shigeyori in Mino Province. Yoshiki's cousin, shogun Ashikaga Yoshihisa, led a military expedition to Ōmi Province in order to subjugate the Rokkaku clan, led by Rokkaku Yukitaka (later Takayori), during which he unexpectedly died of an illness on the 26th day of the third month of Chōkyō 3 (26 April 1489).
With his father, Yoshiki went to Kyoto to claim the title of shogun. Many people, including the former shogun Ashikaga Yoshimasa and kanrei Hosokawa Masamoto disapproved of him, and instead supported the claim of Seikō (later Yoshitō), the son of Yoshiki and Yoshihisa's cousin Ashikaga Masatomo, who was horigoe kubō (堀越公方). However, Yoshiki's aunt, Hino Tomiko, supported him, and when Yoshimasa died in the first month of Entoku 2 (January 1490), it was agreed that he would become shogun on the condition that Yoshimi became a monk. Tomiko had been a member of the shogunal family for nearly 40 years, first as Yoshimasa's wife and later as Yoshihisa's mother. As a result, she occasionally handled governmental affairs on behalf of the shogun. Her support significantly helped Yoshiki become shogun, and she was the person who informed the Imperial Court of his succession.
The new shogun was also opposed by Ise Sadamune, who resigned as head of the mandokoro on 27th day of the fourth month (15 May 1490). Although Sadamune had Tomiko's trust, as he had been a close aide of Yoshihisa since Yoshihisa was a young child and had devoted himself to the former shogun's upbringing, his father, Ise Sadachika, had lost favor after advising Yoshimasa to have Yoshimi killed during the Bunshō incident.
Despite supporting Yoshiki, Tomiko unexpectedly decided to transfer Ogawa palace to Seikō in order to curb the excesses of Yoshiki and Yoshimi, who had suddenly risen to power. Yoshimi was enraged when he found out that Seikō was to inherit the residence, which was a symbol of the shogun, and demolished Ogawa palace and seized the land in the fifth month (May-June), without permission from Tomiko. Tomiko subsequently turned against Yoshimi and Yoshiki, and continued to oppose Yoshiki after Yoshimi's death. Afterwards, on the 26th day of the eighth month (21 September 1490), Yoshiki and Seikō met in person and reconciled. This was due to the efforts of Masamoto and Ashizu Toshiyori, who agreed with Masamoto's intentions.
On the fifth day of the seventh month (2 August 1490), Yoshiki was officially appointed shogun by the Imperial Court while Yoshimi was granted the rank of Quasi-Third Prince, and it was believed that the father-son duo would remain in power. But Yoshimi developed boils in the eleventh month and died on the seventh day of the first month of Entoku 3 (15 February 1491) after treatment proved ineffective. For Yoshiki, his death was a severe blow, as Yoshimi, who had accumulated political experience while commanding the Western Army during the Ōnin War, was a reliable ally. Yoshiki was subsequently forced to think of a way to solidify his political situation on his own. After consulting with his close retainers, he decided to subjugate powerful daimyo to increase his authority.
Ōmi and Kawachi campaigns
Yoshiki continued policies of Yoshihisa, and responded to provincial uprisings in Tanba, Yamashiro, and other provinces in the Kinai region by ordering an attack on Rokkaku Yukitaka in Ōmi Province and strengthening the military. Many daimyo, including the Hosokawa clan, participated in the expedition, successfully overwhelming Yukitaka and driving him to Kōka and then Ise Province. At the same time, because Masamoto opposed the expedition and Masamoto's general Yasutomi Motoie was defeated by the Rokkaku army, Yoshiki began to rely more on other daimyo.
In the first month of Meiō 2 (January-February 1493), at the request of the former kanrei Hatakeyama Masanaga, Yoshiki issued an order to attack Hatakeyama Motoie in Kawachi Province and once again called for the daimyo to provide troops. During the Ōnin War, Masanaga had fought with his cousin Yoshinari over the family succession, dividing the Hatakeyama clan into two warring families, the Sōshū, led by Yoshinari, and the Oshū, led by Masanaga. Masanaga continued to fight with Motoie after Yoshinari's death. Yoshiki responded by accepting Masanaga's appeal for a dispatch of troops, in order to both settle the succession question in Masanaga's favor and reduce his dependence on Masamoto. The daimyo who had been ordered to do so then massed their forces in the capital, but Masamoto did not send troops.
Like with the Rokkaku campaign, Masamoto was opposed to this campaign. The Hatakeyama and Hosokawa clans both had the right to become kanrei, and Masamoto (and, by extension, the Hosokawa clan) benefitted from the division of the Hatakeyama clan, as it reduced their power. For that reason, Masamoto's father Katsumoto had intervened in the succession dispute during the Ōnin War, and reduced the Hatakeyama's power by supporting Masanaga in his fight with Yoshinari. But Yoshiki's Kawachi campaign would reunite the Hatakeyama clan under Masanaga, and the reinvigorated Hatakeyama would once again have the ability to threaten the Hosokawa.
Eventually, Yoshiki overcame Masamoto's opposition, and on the 15th day of the second month of Meiō 2 (3 March 1493), the expedition marched from Kyōto to Kawachi Province. Yoshiki entered Shōgaku-ji on the 24th (12 March), and set up his headquarters there. The daimyo also surrounded and besieged Honda castle (Takaya castle), where Hatakeyama Motoie had established himself. As a result, smaller castles that supported Motoie surrendered one by one, and he was forced into isolation by the third month (late March). Victory for Yoshiki and Masanaga had seemingly become imminent.
But Masamoto colluded with Motoie to prevent the reunification of the Hatakeyama. Masamoto had already been in contact with Motoie's retainers just prior to the start of the Kawachi campaign, and Motoie's chief vassal reportedly boasted on Meiō 2, 23rd of the 2nd month (11 March 1493) that "even if the shogun comes to assault us, this wouldn't even be an issue. That is because Ise Sadamune and all the other daimyo have already reached an agreement with us." Spurred by rumors that Yoshiki would attack him next, Masamoto aligned himself with Akamatsu Masanori and Ise Sadamune, as well as Hino Tomiko.
The coup
On the night of the 22nd day of the fourth month (8 May 1493), Masamoto raised an army. He immediately ushered Seikō to Yushoken, and sent soldiers to the residences of Yoshiki's staff. In addition to these residences, the temples where Yoshiki's younger siblings had been sent were raided and destroyed by the army on the 23rd. According to contemporary records, Tomiko, being midaidokoro of Yoshimasa, assumed direct command and had Masamoto take control of the capital.
Masamoto declared that he was going to depose Yoshiki and support Seikō as shogun, and that Masanaga was relieved of his duties as shugo of Kawachi. On the 28th day of the fourth month (14 May), he had Seikō return to secular life and take the name Yoshitō, supporting him as the 11th shogun.
Yoshiki and the various daimyo, as well as the shogun's followers (such as numerous servants and bugyō), were taken by surprise. When forged documents containing orders to obey the new shogun were sent from Ise Sadamune to Yoshiki's daimyo and servants, most of them returned to Kyoto from Kawachi on the 27th day (13 May). They then assembled under Yoshitō, while none of the daimyo supported Yoshiki except for Hatakeyama Masanaga.
Immediately following Masamoto's actions, it was rumored that Akamatsu Masanori was supporting Yoshiki instead of Masamoto, as he had proactively cooperated in the recent Rokkaku campaign and had an intimate connection with Yoshiki. But because Masanori had married Masamoto's sister Tōshōin prior to Masamoto raising his troops, he ultimately decided to align himself with Masamoto.
Ōuchi Yoshioki, the son of Ōuchi Masahiro, who was the shugo of Suō and Nagato Provinces, also aligned himself with Masamoto. On the first day of the intercalary fourth month (16 May 1493), Yoshioki's sister in Kyoto was abducted by subordinates of Takeda Motonobu. It is possible that, in order to prevent Masahiro (who had fought in the Western Army in support of Yoshimi and Yoshiki up to the end of the Ōnin War) from conspiring with Yoshiki, Masamoto and Motonobu took his daughter as a hostage to force him to consent to the coup.
However, even as the daimyo returned to their provinces, Yoshiki still had 8,000 of Masanaga's soldiers, who remained in high spirits and were prepared to fight to the death. On the third day of the intercalary fourth month (18 May), Takeda Motonobu went to the capital from Wakasa Province to join Masamoto. Around the same time, Akamatsu Masanori and Ōuchi Yoshioki unsuccessfully proposed the idea of having Yoshitō succeed Yoshiki as the latter's adopted son.
Reaction of the Imperial Court
Upon hearing of the event, Emperor Go-Tsuchimikado commanded Shirakawa Tadatomiō, who was the Mōshitsugi and director of the Department of Divinities, to summon three key retainers: Kajūji Norihide, Kanroji Chikanaga, and Sanjōnishi Sanetaka. The Emperor expressed a desire to abdicate, both because he was enraged that the shogun he had appointed had been overthrown, and because Prince Katsuhito (later Emperor Go-Kashiwabara) had come of age. Chikagana and Tadatomiō were against this, with Chikanaga saying "Even if the shogunal family changes and asks difficult things of him, the Emperor's rule is to do as he is told. It would be good if the crown prince were also asked to abdicate by the shogunal family." As a result, the Emperor changed his mind.
For five days starting on the 24th day (10 May 1493), the Imperial Court held a planned discussion on the Amitābha Sūtra, and delayed responding to the coup as the Emperor was listening. On the 28th day (14 May), Hosokawa Masamoto made an imperial visit, and Yoshitō was promoted to Junior Fifth Rank, Lower Grade (従五位下, Ju go-i no ge). At this time, Chikanaga, who was involved with imperial proclamations, mentioned that "if an imperial visitation is not observed, one must not mutually obey." Although a joi donation of 300 bolts of cloth had been made, Yoshitō's proclamation as shogun was postponed because Masamoto had not yet met the necessary expenses.
Masanaga dies and Yoshiki surrenders
On the fifth day of the intercalary fourth month (20 May 1493), Kisen Shūshō resigned from the position of Inryōshiki, which he had held since Bunmei 18 (1486). Ashizu Toshiyori, descended from the Tenjiku branch of the Hosokawa clan, was appointed as his replacement.
On the seventh day of the intercalary fourth month (22 May), Masamoto deployed troops under Uehara Motohide and Yasutomi Motoie to Kawachi province in order to subjugate Masanaga.
Yoshiki and Masanaga were cornered by the Hosokawa army and made a stand at Shōgaku-ji, still maintaining their determination to fight to the end. Yoshiki placed his chambers in the tallest of Shingaku-ji's more than 100 turrets, and the temple was turned into a fortress and its defenses strengthened.
Soon, in the middle of the same month, a large army, including the Negoro-shū, up to 10,000 strong departed from Kii Province, one of Masanaga's territories, and headed towards Shōgaku-ji. However, the Kii forces were forced to stay at Sakai on the way by Akamatsu Masanori. The two armies faced each other at Sakai and began negotiations, but on the 21st (6 June) they started fighting. The Kii forces had several warships that assisted their land forces, and relentlessly attacked the Akamatsu army. In turn, Masanori personally led the Akamatsu forces and fought hard, and after several hours, defeated the Kii army.