Yamato Eikyo War (大和永享の乱)
Yamato Eikyo War occurred in Yamato Province in 1429, in the Muromachi period. It originated from the hostility between the Toyota clan, monk-soldiers of Kofuku-ji Temple Daijo-in, and the Ido clan, monk-soldiers of Kofuku-ji Temple Ichijo-in, and spread to the whole Yamato Province.
Background
The local lords of Yamato Province were either monk-soldiers of Daijo-in or Ichijo-in, the two biggest monzeki (temple formerly led by founder of sect, temple in which resided a member of nobility or imperial family) of Kofuku-ji Temple, or kokumin who were jinin (associates of Shinto shrines) of Kasuga-sha Shrine, but in the period of the Northern and Southern Courts (Japan), they fought each other divided into the Southern Court (Japan) side led by the Ochi clan of kokumin and the Northern Court (Japan) side led by the Tsutsui clan of Ichijo-in monk-soldier. Even after the triumph of the Northern Court side stabilized the Muromachi bakufu (Japanese feudal government headed by a shogun), the conflict lasted between the Tsutsui clan, who won the support from the shogunate, and the Ochi clan, who continued to maintain power especially in the southern part of Yamato Province. Although the shogunate arbitrated the conflict in 1414 upon receiving an appeal from the Kofuku-ji Temple and made Kokujin-shu (local samurai) promise to report to the shogunate and never to have a duel, the fire of conflict continued to simmer.
Seesaw Battle
In August 1429, Toyota 中坊 and a certain Ido started a duel. Kofuku-ji Temple and the shogunate recommended cease-fire in vain and the Ochi clan and the Hashio clan, who took sides with Toyota, attacked the Tsutsui clan and the Tochi clan, who took sides with Ido. The following year, in March 1430, the shogunate ordered Kofuku-ji Temple to subdue Toyota in support of the Ido clan and its related Tsutsui clan but the maelstrom of war expanded, so that the Tsutsui clan and the Hashio clan both attacked the other's castle in September 1431. Shogun Yoshinori ASHIKAGA advised the Hashio clan to withdraw their troops.
The following year, in October 1432, the Tsutsui clan suffered a crushing defeat to the Ochi and Hashio clan, which turned the course of the war against Ido side, but the situation changed after Mitsunobu TSUTSUI appealed to the shogunate. The shogunate reversed its nonintervention policy and decided to subdue the Ochi clan, which led the Ochi clan to fall and escape to the southern Yamato Province. But, after that, Mitsuie HATAKEYAMA, shugo (provincial constable) of Kawachi Province, provided support to Koremichi OCHI and, although the Tsutsui clan sought help from Mochiyuki HOSOKAWA, the Ochi clan regained momentum in 1434 and badly defeated the Tsutsui clan again. In 1435, Yoshinori once again made up his mind to subdue Koremichi OCHI and his allies by the request from Mitsunobu and dispatched the army of bakufu. The Ochi clan barricaded itself in Tonomine, and though having been defeated, continued to resist so much that the army of bakufu led by Mochiari SHIBA was unable to settle the battle even when it went all the way to fight a great battle on June 25, 1437.
Issuance of Rinji (the Emperor's command)
On August 12, 1437 when the shogunate was trying to subdue the surviving retainers of the Southern Court, Yoshiaki, who was at odds with his older brother Yoshinori ran away, so the leaders of the shogunate suspected the involvement of not only Yoshiaki of Gonancho (Second Southern Court) but also Mochiuji ASHIKAGA, Kamakura Kubo (Governor-general of the Kanto region) who was in conflict with Norizane UESUGI, Kanto Kanrei (a shogunal deputy for the Kanto region), because Daikaku-ji Temple (from where Yoshiaki ran away) was associated with the Southern Court and also imperial princes of the Southern Court, Tamagawa no miya and Goshoin no miya ran away, too. On September 17, 1438, they requested the Emperor Gohanazono in strict secrecy to issue Jibatsu Rinji (imperial order to punish enemies) targeting at Tonomine in order to start an all-out assault, which finally ended the war that had lasted for 11 years with the death of Koremichi OCHI in April 1439.
Thereafter
But some people advocate that there is no clear evidence of linkage between the Ochi clan war and Mochiuji and Yoshiaki, and therefore it must be left as an open question. Akira IMATANI infers that the reason why the shogunate claimed the cooperation between Mochiuji and the Ochi clan, who was on the Southern Court side and evidently an Emperor's enemy, was to get the Jibatsu Rinji against Mochiuji because Mochiuji was far from being called as Emperor's enemy. Similarly, concerning the participation of Yoshiaki, there is a theory that regards the running away of Yoshiaki as a mere escape in fear of purge.
This war undermined the authority of Kofuku-ji Temple and strengthened the rule of Yoshinori but, as early as in 1440, the army of bakufu was forced to go back into battle to subdue the Ochi clan who made a move connected with Yuki War. After Yoshinori was murdered in Kakitsu War, Yamato Province again fell into chaos. After that, the Hatakeyama clan and the Ochi clan intervened into the succession dispute of the Tsutsui clan, which further developed into the succession dispute of the Hatakeyama clan, followed by the Onin war, and then, Yamato Province entered the Sengoku period (period of warring states).