Shogun Ahsikaga Yoshimasha, with no heir in 1464, had named his younger brother Yoshimi as successor.

The shogun’s wife bears him a son the following year, however, and asks daimyo Yamana Souzen Mochitoyo for his support in promoting her son’s claim.

Daimyo Hosokawa Katsumoto, Yamana’s son-in-law, supports Yoshimi.

The powerful Tendai, a Japanese school of Mahayana Buddhism, one of several Buddhist sects in Japan, have since the ninth century wielded authority from their monasteries on the Hiyesian, a large hill northeast of the Japanese capital of Kyoto.

The rival Shin sect, founded by the former Tendai Japanese monk Shinran Shonin and well established in the capital itself, has for decades been the Tendai’s major competitor for power, land, and influence.

Both sects have warrior monks, but the shoguns have in past times kept their aggressions from boiling over.

Now, with the shoguns reduced, like the emperors, to mere figureheads, antagonism between the two sects evolves into open conflict.

Marching down into Kyoto in 1465, the monks of Hiyesian torch the Shin’s Hongwanji Temple headquarters, burning it to the ground.

The different sects also war with one another on the Japanese countryside, destroying property.

As a result, the Shin would have to stay in the countryside for one hundred and twenty-five years.

This will prove a boon: their following again will grow enormously among ordinary people, especially in the Hokuriku region.

Today, Shin Buddhism is considered the most widely practiced branch of Buddhism in Japan.

A dispute between Hosokawa Katsumoto and Yamana Sōzen, which begins in 1467, will escalate into a nationwide war involving the Ashikaga shogunate and a number of daimyo in many regions of Japan, initiating Japan’s Sengoku jidai, "the Warring States Period".

The deposed shogun Yoshiyoshi had turned to Yamana Sozen Mochitoyo for help in 1466.

Yamana and Hino Tomiko, the official wife of Yoshimasa, influence the shogun to remove Hatakeyama Masanaga as Kanrei in January of 1467.

In response, Masanaga and Hosokawa Katsumoto, Yamana’s son-in-law, raise an army.

The shogun has forbidden Hosokawa to aid Masanaga, who attacks Yoshiyoshi without him, is defeated, and escapes to Kyoto.

The shogunate has long forbidden battles between daimyo, and this flouting of the rules leads to open fighting between rival daimyo factions and the speedy disintegration of the Muromachi shogunate’s authority.

Hosokawa raises an army in May, seizes the shogunate residence of Hana-no-Gosho, and coerces the shogun into proclaiming for Hosokawa’s side and denouncing Yamana as a rebel.

Ouichi Masahiro, another leading daimyo, supports Yamana by marching his army to Kyoto, rescuing Yoshinao from Hosokawa and proclaiming him the new shogun.

The battle at Kyoto ends in stalemate, but fighting in what is called the Onin War escalates throughout Japan.

The fighting has become serious by July 1467, which is when the Ōnin War is said to have begun.

The Yamana and Akamatsu clans vie for control of the Hizen and Harima district while the Hosokawa and Kono houses dispute the possession of the Iyo district.

The Akamatsu side with Hosokawa Katsumoto in the contest for the shogunate; the Kono side with his father-in-law, Yamana Souzen Mochitoyo.

Kyoto's northern parts are in ruins by September, and everyone who can flee from Kyoto does so.

Authority in Japan is diffused to local military leaders, the daimyo, when the Ashikaga lose control of their vassals after 1467.

The dispute between Hosokawa Katsumoto and Yamana Sōzen escalates into a nationwide war involving the Ashikaga shogunate and a number of daimyo in many regions of Japan

The shogun Yoshimasa, who has reigned since 1440, simply turns his back on the troubles in Japan.

In 1473, he retires to his estate on the outskirts of Kyoto, where he builds the Silver Pavilion (“Ginkaku”) and becomes the patron of a remarkable artistic flowering.

The Japanese civil war between the two daimyo, called the Onin War, spreads rapidly throughout the nation even after the deaths, in 1473, of opposing war leaders Hosokawa Katsumoto and his father-in-law, Yamana Souzen Mochitoyo.

The war, involving more than a dozen great clans, notably the Hatakeyama and the Shiba, rages for a decade, during which time most of Kyoto is burnt to the ground.

The Hosokawa and Yamana clans agree to an armistice in 1477, officially ending the war, but many of the daimyo continue to struggle in other regions for the redistribution of feudal power.