The Ōnin War was fought between the families of two samurais who were close to the Ashikaga Shogun of Japan. By 1467, the year that war began, the Ashikaga dynasty had grown so weak that a succession dispute provided the trigger for unrest and the collapse of central authority. The ensuing civil war, fought from 1467 to 1477, largely within the imperial capital of Kyōto, was the precursor of the so-called Age of Warring States.
Each of the contending samurai factions had a mansion that acted as a military base within Kyōto, where the Shogun was also located. The first was Yamana Sōzen, nicknamed the Red Monk. His rival was his son-in-law, Hosokawa Katsumoto. The spark for their conflict was a succession dispute within the Shogun’s own family, one faction favoring the Shogun’s brother, the other his son.
The fighting began when the Hosokawa family, commanding an army estimated at 160,000 attacked the mansion of Isshiki, one of the Yamana generals, which lay across the street. The battle consisted of arrow exchanges, swordplay, and the use of fire. Soon the rivals, with the Yamana at the head of any army of about 110,000, were facing each other across a charred wasteland. Sporadic fighting took place for about a year.
The recently renewed contact with China, severed during the Mongol invasions, allowed several Chinese weapons to appear in Japan. The first were exploding arrows launched by catapult, while in 1468 there is a record of fire-spears being used.
The Ōnin War dragged on with sporadic attacks as the fighting spread to neighboring province. Where the families had fought, looting mobs moved in, leaving the imperial capital almost in ruins. Yamana and Hosokawa both died in 1473, but by then the cause of their dispute was almost forgotten. Many people suffered during the 11-year-long war, and the Yamana clan in particular was bled dry. The city of Kyōto itself was devastated, its shrines and temples looted and most of its surviving populace forced to take refuge in nearby cities long after the fighting had ceased.
Losses: No reliable figures.