The Meio Incident (明応の政変)
The Meio Incident involved the enthronement and dethronement of the Ashikaga seii taishogun (literally, "great general who subdues the barbarians") and occurred in the Muromachi period in 1493. In recent years, in the field of Japanese history there is an influential theory that regards this incident as the beginning of the Sengoku period (period of warring states).
Conflict over the post of shogun
Yoshitane ASHIKAGA was the heir of Yoshimi ASHIKAGA, who was backed by the leader of Western forces during the Onin War. When the war was resolved as the Western forces were outnumbered, he and his father escaped to Mino Province, relying on Shigeyori TOKI. The ninth shogun, Yoshihisa ASHIKAGA, at the head of a force of provincial military governors turned daimyo and shogunal guards, led a campaign against the Rokkaku in Omi Province, but died there in 1489 of an illness.
Yoshiki returned to Kyoto with Yoshimi and was put forward as the tenth shogun, but some people, including Yoshimasa ASHIKAGA and Masamoto HOSOKAWA, supported Seiko (Yoshizumi ASHIKAGA), the son of Masatomo ASHIKAGA who was the Horikoshi Governor-General, and was the head of the Kyogon-in of Tenryu-ji Temple at that time. However, Tomiko HINO supported her nephew Yoshiki, and after the death of Yoshimasa the following year, in 1490, Yoshiki was chosen to be the tenth shogun on, among others, the condition of Yoshimi becoming a monk.
Masamoto, Sadamune ISE and others who had been against this decision opposed Yoshimi and his son. Yoshiki followed the policies of the former shogun Yoshihisa and tried to increase his military strength, by taking over the campaign against the Rokkaku house in 1491 to deal with uprisings like in Tanba and Yamashiro provinces in the Kinai region.
In 1493, Masanaga HATAKEYAMA requested that Yoshiki subjugate Kawachi Province to defeat his opponent, Yoshitoyo HATAKEYAMA (the son of Yoshinari HATAKEYAMA). Although Masamoto was against this request, Yoshiki marched off with a punitive force to settle the issue of the succession to the head of Hatakeyama clan.
Masamoto gained the cooperation of Tomiko and Masanori AKAMATSU, who had begun to feel dissatisfied with Yoshiki, and then pulled off a coup d'etat by making Seiko return to secular life and helping him become the eleventh shogun. He also brought Kyoto under his control. Yoshiki's forces were divided by this news. After Masanaga died, Yoshiki surrendered and it was decided that he was to be confined in Ryoan-ji Temple in Kyoto.
In June of the same year, Yoshiki, who had been confined, went from Kyoto to Hojo-du, Izumi county, Ecchu Province with the help of his close aides, relying on Naganobu JINBO, a chief vassal of Masanaga and deputy of the divided counties Nei and Izumi who had been appointed by a shugo. Furthermore, over 70 people including vassals of the shogun, Jikkin Kugeshu (昵近公家衆), Zen monks, etc., who were close to Yoshiki, followed his move to Ecchu (the Ecchu Governor-General).
Due to this incident, Masamoto took over shogunal administration, and the authority of the shogun whose military foundations, such as shogunal guards, had broken down, became weaker because of the bakufu's governmental authority being divided into two. This caused conflicts all over the country among supporters of the shogunal family that divided into two lines. After that, shogunal administration was supported by the Hosokawa clan's power.
Also, in connection to this, the military governor of Yamashiro, Sadamichi ISE (the son of Sadamune), who was close to Yoshiki, won over the local samurai class who had led an uprising in Yamashiro Province and tried to resist Masamoto, and Masamoto used the same technique as a countermeasure. Due to this, the local samurai class divided into an Ise faction and a Hosokawa faction, and the following year the uprising in Yamashiro Province was forced to disband.
Moreover, recently there is an influential theory that the invasion of Izu Province by Soun HOJO, a vassal of the Imagawa clan, that occurred in the same year, in cooperation with Masamoto and Sadamasa UESUGI, was intended to defeat Chachamaru ASHIKAGA, who was the Horikoshi Governor-General and Yoshizumi's brother by a different mother, and opposed Yoshizumi.
Similarly, in recent years there is an influential theory among Japanese historians, that the Meio Incident was not only a coup d'etat in the central government but also a critical turning point, which led to social upheaval and rebellions against the ruling classes, especially in the eastern provinces, and was the initial stage of the Warring States period.