The Koryaku Coup (康暦の政変)
The Koryaku Coup was a coup d'etat that occurred in 1379 (the fifth year of Tenju (Southern)/first year of Koryaku (Northern)) during the period of the Northern and Southern Courts (Japan), in which the Kanrei, or deputy (de facto leader) of the Muromachi Shogunate, Yoriyuki HOSOKAWA, was overthrown and lost his position.
During the reign of the Muromachi Shogunate's second Shogun Yoshiakira ASHIKAGA, a conflict had arisen among the group of shugo (Protectors), and after such men as the steward Kiyouji HOSOKAWA were driven out of power, they defected to the Southern Court at Yoshino, who managed to recapture Kyoto, which left the shogunate in a very unstable position. After Kiyouji was overthrown, the reins of political power were held by a father-son pair, Takatsune and Yoshimasa SHIBA, but they clashed with Doyo SASAKI, and were themselves driven from power during the Joji coup. Just before Yoshiakira died, Yoriyuki HOSOKAWA, who had been fighting the Southern Court forces on the island of Shikoku and in the Chugoku region (of western Japan), was appointed Kanrei after obtaining the support of Sasaki and others of the anti-Shiba faction. Yoriyuki acted as advisor and regent to Yoshiakira's son Yoshimitsu ASHIKAGA, who was still a child, and carried out policies like experimenting with a new hansei (half-tax) law, which was designed to protect existing land holdings, and he attempted to negotiate with the Southern Court, but he also became embroiled in a religious conflict between Mt. Hiei, the powerful old Buddhist sect, and Nanzen-ji temple, a center of the rising new Zen sect; he opposed the Mt. Hiei faction because he was supporting the Nanzen-ji faction, yet he also clashed with Nanzen-ji's own powerful religious leaders, for example, when he opposed chief priest Myoha Shunnoku's seclusion from public life.
In 1376, Yoriyuki made his younger brother Yorimoto HOSOKAWA supreme military commander and dispatched him to counter the Southern Court's military maneuvers in the Kii peninsula, but Yorimoto failed to subjugate the area, and the third Shogun Yoshimitsu, who had now reached adulthood, had the leader of the Yamana clan, a member of the anti-Yoriyuki faction, to sent as a replacement; moreover, he granted appointments to others of the anti-Yoriyuki faction, including Yoriyasu TOKI and the rehabilitated Yoshimasa SHIBA, to command military activities in Yamato. The following year, in 1377, when riotous strife within Yoshimasa's territory spread like wildfire to Ota estate (modern-day Toyama City in Toyama Pref.), part of Yoriyuki's territory, the antagonistic dispute between Yoriyuki and the Shiba faction, Toki, the Yamana clan, and others flared out into the open, and some shugo switched from the Yoriyuki faction to the Shiba faction. The anti-Yoriyuki faction asked Yoshimitsu for permission to expel and subjugate Yoriyuki, and when Takahide SASAKI, who had switched to the anti-Yoriyuki faction, raised an army at Omi, Ujimitsu ASHIKAGA, the Shogun's representative at Kamakura, prepared to begin military action in response, it also happened that Noriharu UESUGI committed suicide to remonstrate with him about this course of action. When Yoshimitsu pardoned several, including Takahide and Yoriyasu, under pressure from Yoshimasa and others, the anti-Yoriyuki faction, and Yoshimasa first among them, gathered their military forces together and surrounded the Shogun's flower garden at his estate, insisting that Yoshimitsu dismiss Yoriyuki. Yoriyuki took the tonsure, burned down his own estate, and went off together with his family to his territories in Shikoku.
The successor as kanrei was Yoshimasa, and among others, Myoha Shunnoku returned to public life. Yoriyuki, after going off to Shikoku, fought with the Kono clan of Iyo Province, who had received a shogunal order to hunt him down and kill him; however, at the end of the year, Yoriyuki received a pardon. But given that his younger brother Yorimoto HOSOKAWA assumed the position of kanrei, and the fact that Yoriyuki himself was eventually able to stage a political comeback and return to the inner circle of the shogunate, it is thought that this coup may have been instigated by Yoshimitsu, who wished to achieve independence from Yoriyuki. It is thought that Yoshimitsu played the Shiba and Hosokawa clan factions off against each other, using their mutual antagonism to check them both and keep either from becoming too powerful.
After the coup, Yoshimitsu established the Hokoshu, a Shogunal army directly loyal to him, and succeeded in using it to weaken the two most powerful shugo families, the Yamana clan in 1391 during the Meitoku Rebellion and the Ouchi clan in 1397 by means of the Oei Rebellion, thereby solidifying the shogunate's control over the country.