Onin

Onin is the name of a Japanese era (nengō) used during the Muromachi period. The Onin era lasted from 1467 to 1469 and was followed by the Bunmei era, which began in 1469. The era name is written with the kanji 応仁.

The Onin era is best known for the Onin War (Onin no ran), a prolonged civil conflict that began in 1467 and centered in Kyoto. The war pitted the Hosokawa clan, led by Hosokawa Katsumoto, against the Yamana clan, led by Yamana Sozen, and drew in many other powerful families and local lords. Fighting and political maneuvering during the war caused widespread destruction in the capital and surrounding areas, and the conflict dragged on for more than a decade, extending beyond the end of the Onin era itself.

The broader impact of the Onin War was a marked weakening of central authority under the Ashikaga shogunate and the fragmentation of political power. As centralized control waned, regional warlords began to assert greater independence, contributing to the onset of the Sengoku period, a century-long era of nearly constant military conflict and territorial realignment across Japan.

Because era names were often chosen for symbolic reasons, the precise meaning of Onin—composed of the characters for “respond” or “obey” and “benevolence”—is tied to courtly symbolism rather than a straightforward historical summary. The Onin era thus marks a transitional moment: a short nominal period that coincided with a crisis of governance and the opening of a long era of regional disorder.