Uesugi The War of Zenshu (上杉禅秀の乱)
The War of Zenshu UESUGI was the war that broke out in the Kanto region in 1416, the Muromachi period. It was a rebellion against Mochiuji ASHIKAGA, Kamakura kubo (governor-general of the Kanto region) instigated by Ujinori (a.k.a Zenshu) UESUGI, former Kanto kanrei (assistant to Kamakura kubo). Zenshu is the Buddhist name of Ujinori UESUGI.
Details
Kamakurafu was an organization set up by the Muromachi bakufu (feudal government headed by a shogun in the Muromachi period) in order to rule the Kanto region in the period of the Northern and Southern Courts (Japan). Kamakura kubo was assisted by Kanto kanrei, and the post of kanrei was basically hereditary to the Uesugi clan. In 1409 the third shogun Mitsukane ASHIKAGA died, and Mochiuji, his child, became the new kubo. Ujinori UESUGI (from the Inukake Uesugi family), who had been Kanto kanrei, had resigned in opposition to the Kamakura kubo the previous year. Subsequently Norimoto UESUGI (from the Yamanouchi Uesugi family, a rival of the Inukake Uesugi family) succeeded the kanrei post. Ujinori then approached Mitsutaka ASHIKAGA (Mochiuji's uncle) and Mochinaka ASHIKAGA (adopted child of Mitsutaka and younger brother of Mochiuji), also gained Mitsuzumi IWAMATSU (Ujinori's son in-law), Ujiharu NAGAO, the Chiba clan, the Utsunomiya clan, the Oda clan, the Sagami Miura clan, the Takeda clan and Kokujin-shu (local samurai) over to his side and revolted against Mochiuji in 1416.
On October 31, 1416 around Dog Time (8:00 - 10:00 pm), Mitsutaka ASHIKAGA entered Hoju-in Temple near Kamakura Gosho (Mochiuji's residence) and took up arms. Mitsutaka together with Ujinori went to capture Mochiuji and Norimoto, however Mochiuji and others had already escaped led by their retainers (according to "Kamakura Ozoshi"). After that, Ujinori and Mitsutaka took control of Kamakura together with the soldiers recruited from various clans.
Mochiuji, who escaped to Suruga expecting the protection of Norimasa IMAGAWA, was supported by the bakufu. The soldiers of the Imagawa clan, the Echigo Uesugi clan, the Satake clan and the Utsunomiya clan went to subdue Mitsutaka and Ujinori on the order of the bakufu. Consequently Ujinori and others attacked Suruga Province but they were defeated by the Imagawa clan. Furthermore the samurai group pushed by the Uesugi clan and others, including the Edo clan and the Toshima clan in Musashi Province, hailed each other and expelled the force of Ujinori from Musashi. In the following year of 1417, the Battle of Seyahara on the New Year's Day, Ujinori's troops rallied as they defeated the united force of the Edo and Toshima clans. However the Imagawa army invaded the Sagami region at an unguarded moment, and the clash was brought to an end on February 5, by the suicide of Ujinori, Mitsutaka, Mochinaka and others in Yukinoshita, Kamakura. Their defeat in the battle led the Inukake Uesugi clan to die out.
(However, some of Ujinori's children survived by entering the priesthood where they were put under the patronage of the bakufu.)
Also Mitsuzumi IWAMATSU and Nobumitsu TAKEDA were killed by a search-and-destroy troop.
The effects of the War of Zenshu
The fourth Shogun of the Muromachi bakufu, Yoshimochi ASHIKAGA, supported Mochiuji in the war. There was the incident of Yoshitsugu ASHIKAGA, who was the younger brother of Yoshimochi, running away and leading to Yoshitsugu's capture and confinement. It caused such a stir that the name of the person suspected to have secretly communicated with Ujinori UESUGI inside the bakufu was mentioned.
Muromachi bakufu
Yoshitsugu ASHIKAGA, who feared for his safety after the death of Ujinori, escaped from Kyoto in 1417. However he was soon captured in Takao (Kyoto City) by Mitsunari TOGASHI, a close attendant to Yoshimochi. Yoshitsugu was moved from Ninna-ji Temple and confined in Shokoku-ji Temple, and on October 20 (old calendar) was forced to enter the priesthood. However in November (old calendar) the report from Mitsunari TOGASHI, Yoshitsugu's interrogator, caused a problem. The report said that together with Yoshitsugu, there were the present kanrei, Mitsumoto HOSOKAWA and a former kanrei Yoshinori SHIBA, Mitsunori HATAKEYAMA, Yoshinori AKAMATSU, Yasumasa TOKI, Tokihiro YAMANA and also the court nobles such as Noritaka YAMASHINA and Mochimitsu HINO conspired and plotted to overthrow Yoshimochi working together with Ujinori UESUGI.. In response to the report, Mochiyori TOKI (Yasumasa's legitimate child) was removed from his position as shugo of Ise Province. Also dominant shugo (military governors) including Mitsumoto and others, and court nobles, were all either put under house arrest or exiled. In the following year, 1418, Yoshitsugu was killed by Mitsunari TOGASHI on the order of Yoshimochi. However, in November of that year, Mitsunari TOGASHI was himself under suspicion, that he had assisted Yoshitsugu and also committed adultery with Yoshimochi's wife, 林歌局 and for this he was expelled. Some consider that this was a counter-coup by dominant shugo guardian feudal lords, Hosokawa amongst others, who were disempowered following the accusations of Yoshimochi and a group of his attendants, including Mitsunari TOGASHI.
(Both Mitsunari TOGASHI and Mochisada AKAMATSU, close attendants of Yoshimochi, were accused of adultery with a wife of Yoshimochi, and AKAMATSU received his downfall related to another case later.)
Mitsunari TOGASHI fled to Mt. Koya, but was killed by the subjugation of Mitsuie HATAKEYAMA on February 28, 1419.
Kamakura kubo (Governor-general of the Kanto region)
The stance of the Muromachi bakufu towards this rebellion was that they took the step of killing Ujinori because of their fear of his coalition with Yoshitsugu and the Southern Court. In reality they did not truly support Mochiuji, the Kamakura kubo. This is because Mochiuji also had started to deny the authority of the central bakufu by strengthening the power and basis of his regime against the armed uprisings which were breaking out in various areas in Kanto and Oshu regions during the confusion of the central bakufu. As the fact that the bereaved child of Ujinori, who was believed to have been searched out and killed by the bakufu, but who had actually been protected by the bakufu. The bakufu acted as this in case Mochiuji took action against them.
In the year after Zenshu's death, the uprising called 'Kazusa no Hanikki' led by his former retainers, the local lords, broke out in Kazusa Province, one of Zenshu's feudal estates. After that Mochiuji hunted the remaining attendants of Ujinori, including the Iwamatsu clan and the Satake clan (originating from the Yamairi clan), and purged the opponents in Kanto region including territorial lords belonging to Kyoto fuchishu (samurai in Kanto and Tohoku regions who were direct vassals of Shogun).
(This event is sometimes called the 'Oei War')
At the same time Mochiuji started acting independently. The bakufu monitored Kamakura kubo on issues such as the appointment of a provincial constable. Also there were continual clashes of opinion between Kamakura kubo and Kanto kanrei. The disturbances in the Kanto region continued, such as the Eikyo War in 1438 and the Battle of Yuki in 1440.