Meiō incident

The Meiō incident, or Meiō coup (Japanese: 明応の政変, Hepburn: meiō no seihen), was a late 15th century coup d'état in Japan, when deputy-shogun Hosokawa Masamoto deposed the tenth shogun of Japan, Ashikaga Yoshitane. On the night of 9 May, 1493, Masamoto raised troops in Kyoto. With support from Hino Tomiko and Ise Sadamune, he deposed Yoshitane (at the time Yoshiki), installing Ashikaga Yoshizumi (at the time Yoshitō) as the new shogun. Although the coup was initially successful, Yoshitane escaped from house arrest in Kyoto and established himself in Etchū Province. Masamoto failed to decisively defeat him again, effectively splitting Japan between two rival governments. Masamoto also faced internal opposition from the Awa branch of the Hosokawa clan, especially after he adopted an heir from outside the clan. In 1507, Masamoto was assassinated, and Yoshiki deposed Yoshitō the following year.

The primary cause of the Meiō incident was that Yoshitane continued fighting military campaigns despite Masamoto's objections, particularly his campaign against Hatakeyama Yoshitoyo in Kawachi Province. The aim of the campaign was the reunification of the Hatakeyama clan under Hatakeyama Masanaga, which Masamoto opposed because the Hatakeyama clan was the most powerful rival to the Hosokawa clan for the position of kanrei. In addition, Yoshiki had begun to rely more on other daimyo, including Masamoto's rival Hosokawa Yoshiharu, with the intention of reducing his dependency on Masamoto.

The coup and the subsequent conflict heavily reduced the shogunate's power over the daimyo, as it was forced to rely on the support of powerful clans. The Hosokawa clan was divided into two warring factions after Masamoto's death, while the Ōuchi clan under Ōuchi Yoshioki reached the height of its influence. In addition, the shōgun-ke (将軍家; family members of the shogun who could succeed him) was subsequently divided into those descended from Yoshitō and those descended from Yoshiki.