Tainei-ji incident participant Ōuchi Yoshitaka
The Tainei-ji incident (大寧寺の変, Taineiji no Hen) was a coup in September 1551 by Sue Takafusa (later known as Sue Harukata) against Ōuchi Yoshitaka, hegemon daimyō of western Japan, which ended in the latter's forced suicide in Tainei-ji, a temple in Nagato Province. The coup put an abrupt end to the prosperity of the Ōuchi clan, though they ruled western Japan in name for another six years under the figurehead Ōuchi Yoshinaga, who was not related to the Ōuchi by blood.Background
The Ōuchi clan was one of the most powerful and important families in Japan during the reign of the Ashikaga shogunate in the 12th to 16th centuries. Expanding out from Suō Province towards the western end of Honshu, the Ōuchi domains at their height comprised six provinces. They were among the primary families involved in foreign trade and relations, particularly with China. Under the patronage of the 31st family head Ōuchi Yoshitaka, the Ōuchi home city Yamaguchi prospered greatly from the cultivation of the arts and foreign trade, attracting famed artists, Chinese merchants, and Jesuit missionaries (such as Francis Xavier) to his city.At the same time, Yoshitaka fostered a close relationship with Emperor Go-Nara in Kyoto, and sponsored many imperial rites that the imperial court could not have afforded otherwise. On March 27, 1551, the embattled emperor appointed Ōuchi Yoshitaka as Acting Governor of Yamashiro (山城権守), the home province where the imperial capital Kyoto was located, in a bid to leverage the Ōuchi against the ravages of the warlord Miyoshi Nagayoshi, who occupied the capital. Yoshitaka, as Acting Governor of Yamashiro and, by extension, the protector of the court, embarked on a daring plan to relocate the emperor and the court to Yamaguchi. High-ranking courtiers and performers of imperial rites moved to Yamaguchi, including dignitaries such as former regent (kampaku) Nijō Tadafusa and retired Grand Minister (Sadaijin) Sanjō Kin'yori (三条公頼; father-in-law of Takeda Shingen). By the end of the eighth month of 1551, nearly the whole court, save for the emperor himself and the palace ladies, was in Yamaguchi.The military establishment of the Ōuchi opposed Yoshitaka's plan to settle the imperial court in Yamaguchi: such a move would see privileges accorded to the courtiers and undermine the military's standing in the Ōuchi clan. In addition, the plan was prohibitively expensive. This faction, represented by Sue Takafusa, also felt that Yoshitaka had become "weak" due to his complete obsession with the arts to the detriment of military matters after the failed siege of Toda Castle in 1543 against the Amago clan. Sue Takafusa, one of Yoshitaka's deputy shugodai, also took personal offence at the rise of the calligrapher Sagara Taketō, who benefitted from Yoshitaka's inward turn toward literary and courtly pursuits.
Takafusa's dissatisfaction was such that another of Yoshitaka's shugodai, Sugi Shigenori (杉重矩), warned that Takafusa had started conspiring against Yoshitaka by extension. However, Yoshitaka dismissed the threat, which caused Shigenori to lose confidence in Yoshitaka's judgement and to throw his lot in with Takafusa. Yoshitaka apparently placed his faith in his ally Mōri Motonari to come to his rescue in case trouble came from within; he did not know that Takafusa had already gotten Motonari's tacit approval for his coup. At the eve of his rebellion, Takafusa not only gained the support of fellow Ōuchi shugodai Sugi Shigenori and Naitō Okimori (内藤興盛), but also that of the Ōuchi's rival daimyō Ōtomo Sōrin in Kyushu. He was also supported financially by the merchants of Sakai, who were incensed at Yoshitaka's tolerance and patronage of the Murakami pirates collecting tolls on the Seto Inland Sea's traffic lanes.