The Ōnin War

Visualizing 12 Years of War in Japan, 1465-78

The Ōnin War: Visualizing 12 Years of War in Japan, 1465-78

This website offers a new perspective on the Ōnin War. This war, which nominally lasted from 1467 through 1477, led to the destruction of Kyoto, Japan’s capital, and according to standard narratives, ushered in a century of conflict, Japan’s Warring States (Sengoku) era.

The Chronicle of Ōnin provides the basic narrative of the war. It suggests that under the feckless rule of Ashikaga Yoshimasa and his greedy wife Hino Tomiko, two factions of warlords, led by the Yamana and the Hosokawa, vied for hegemony. The war began on 1.15.1467, when two factions of the Hatakeyama fought at the Kami Goryō shrine, and led to the devastation of Kyoto.  Both commanders, Yamana Sōzen and Hosokawa Katsumoto, perished in 1473, and thereupon the war lasted for four more years, until the surviving participants abandoned Kyoto and returned to their home provinces.

Nevertheless, this Chronicle was not written by an eyewitness, but was created approximately a generation after this war ended. This project is aimed to illustrate instances where warriors can be verified as fighting in military conflicts.

The picture, as you shall see, differs greatly from the conventional Ōnin  narrative in several ways. First, the wars began in the west in 1465, and lasted through 1478. Second, most of the fighting occurred in western Japan, and near the ports of Hyogo and Sakai, rather than Kyoto itself. The port of Tōsai, located near modern day Hiroshima, was a crucial source of conflict, and it would be fought over from 1466 through 1477. Finally, Ōuchi Masahiro, a commander based in Yamaguchi, had a central role in the conflict. Not only was he involved in the battles of 1465 and 1466, but his advance on the capital in 1467 led to the dominance of his army until 7.6.1471, when Masahiro’s  uncle  Ōuchi Dōjun rebelled at Akamagaseski, forcing him to send back forces to the west. Masahiro maintained a presence in Kyoto, and ultimately achieved all of his objectives, retreating from the capital in 1477, although he did not fully pacify the west until 1478.

A note on reading this map. Flames depict verifiable military encounters. Larger flames denote longer lasting battle at the same place. Instances where movement can be verified in military documents are depicted with arrows. Finally the time of the conflict is a rough approximation, as not all days are timed identically. In particular, the latter years of the war, where conflicts are geographically rarer, but lasting longer, are depicted according to a compressed timeline. Music only can be heard during the advance of Masahiro’s armada to Kyoto in 1467.


This site can be viewed in two ways. One can either view the video of the war itself or click on particular dates that are located to the right to view particular moments of the twelve year conflict.

This site was created under the auspices of a Research Grants from the University Committee on Research in the Humanities and Social Sciences. Although research was accomplished by Thomas Conlan, Kevin Travers ( / Kevin Travers Creative Design Photography) masterfully conceptualized and animated this video. Ben Johnson provided great support in creating this website. Any errors are solely the responsibility of Thomas Conlan. For comments or questions, please email me at