A decade of civil war in Kyoto sparked Japan’s era of warring states
The Ōnin War began as a succession dispute between two powerful clans, but it quickly spiraled into a nationwide catastrophe. As Kyoto burned, the central government collapsed, empowering local warlords and emboldening peasant uprisings. This ten-year struggle shattered the old order and ignited a century of relentless, decentralized conflict across Japan.
The Ōnin War, lasting from 1467 to 1477, was triggered by a complex succession crisis involving the 8th shogun, Ashikaga Yoshimasa. Initially, Yoshimasa named his brother, Ashikaga Yoshimi, as his heir. However, the 1465 birth of Yoshimasa’s son, Yoshihisa, created two competing factions. Hosokawa Katsumoto supported the shogunate’s established line, while Yamana Sōzen backed the infant Yoshihisa. These personal rivalries, compounded by existing disputes within the Hatakeyama and Shiba clans, exploded into open warfare in Kyoto.
The conflict was characterized by a brutal stalemate. By 1467, the Eastern Army under Hosokawa and the Western Army under Yamana were evenly matched, with tens of thousands of troops mobilized. The fighting reduced much of Kyoto to ruins, destroying historic monasteries like the Shōkoku-ji. Even after both primary leaders died in 1473, the war dragged on until 1477, when the Ōuchi clan finally withdrew. The shōgun, Ashikaga Yoshimasa, remained largely detached, focusing on cultural pursuits and the construction of his Silver Pavilion while the capital descended into lawlessness.
The war’s most significant legacy was the phenomenon of gekokujō, or 'the low oppress the high.' As central authority disintegrated, the vacuum was filled by local uprisings, such as the Yamashiro-ikki and the Ikkō-ikki, where peasants and lesser samurai seized control of provinces. The Ashikaga shogunate became a mere puppet for the Hosokawa family, and the fighting spread far beyond the capital. This era, known as the Sengoku period, saw Japan transformed into a collection of quasi-independent states where vassals frequently betrayed their lords, setting the stage for a century of endemic civil strife.
Source: Ōnin War
