A precursor to the Sengoku Jidai, the Onin War began as a quarrel between two rival families who used succession over the shogunate as an excuse to destroy each other. The conflict escalated until it enveloped Kyoto itself, almost destroying it. The Ashikaga shoguns became mere puppets after the Onin War but something more serious had happened as Japan fragmented into independent states heralding the beginning of the Sengoku Jidai.

With the bakafu based in Kyoto and so many powerful magnates living there as a result it was inevitable that some disagreements were bound to explode into violent war. This is what happened between the Yamana and Hosokawa families. Why they originally came to blows is unclear but their part in the Onin War (named after the first year of the Onin era) is well known. Shogun Ashikaga Yoshimasa, not one for the political highlife, wanted to retire but he had no son to pass the title onto. To counter this problem Yoshimasa named his brother, Yoshimi, as his successor. A year later, however, Yoshimasa's wife gave birth to a son called Yoshihisa and from this moment on Kyoto divided into two vast armed camps. Yamana Sozen Mochitoyo, head of the Yamana faction, supported Yoshihisa; while Hosokawa Katsumoto, head of the Hosokawa faction, supported Yoshimi.

Yamana Sozen was a samurai monk and was famous for his aggression and frequent fits of anger for which his face would turn bright red. His fiery temperament earned him the nickname of the 'Red Monk'. How different he was to his son-in-law Katsumoto, whose temperament was calm and collected. Both sides looked for houses in the capital to use as headquarters and observed the streets for their strategic worth. At the end of February 1467 the battle started: a mansion belonging to one of the Hosokawa generals went up in flames. In April Hosokawa samurai attacked a group of Yamana troops who were bringing rice into the city. The tinder had now been lit and everyone who could began to evacuate Kyoto leaving it to the two warring camps. Rumours that Sozen would attack the imperial palace forced Katsumoto to take the emperor and the retired emperor to the safety of the bakufu headquarters. The rumours were well-founded as Sozen did conduct a raid on the imperial palace but must have been disappointed to find that the imperial family were not in residence. At the end of May the Hosokawa attacked the mansion of a Yamana general and it was not long before it went up in flames along with the entire block that surrounded it.

Over the coming weeks Kyoto was looted and pillaged and by the end of July much of the north was reduced to rubble and ash. As the houses disappeared barricades were constructed across the streets and trenches were dug so that it looked like something out of the First World War and both sides attacked and retreated from them. After receiving reinforcements Sozen then attacked the monastery of Shokoku-ji where many of his enemies had fortified themselves. The fighting was intense until at night both sides retired exhausted. By now the carnage in Kyoto was terrible as the streets were choked with corpses and carts were filled with severed heads. In the first few months of 1468 there was moderate calm as both sides glared at each other between the trenches. The Hosokawa used trebuchets to bombard the entrenched Yamana positions with exploding bombs and rocks. Katsumoto managed to convince the shogun to declare his bitter enemy, Sozen, a rebel but the Red Monk controlled all the exits from the ancient capital and the stalemate continued for months.

The deaths of both Yamana Sozen and Hosokawa Katsumoto in 1473 did not halt the war. However, by this time the label of rebel was dispiriting the Yamana faction so much so that one of its generals, Ouchi Masahiro, burnt down his section of Kyoto and promptly departed. The once great city, by 1477, was stripped bare as mobs took advantage of the anarchy. The shogun Ashikaga Yoshimasa did nothing to halt the decline of his city and instead spent his time in leisure and overseeing the construction of the Silver Pavilion, which he hoped would rival his grandfather's Golden Pavilion in its beauty. To his disappointment there was not enough money to finish lining it with silver, so to this day it remains black. The Onin War finished in 1477 but the damage had already been done to the Ashikaga Shogunate as it became mere puppets of the Hosokawa family. They made and broke shoguns over the many years that they were in control of the bakufu, even fighting amongst themselves to put their candidate forward for the title.

Encouraged by the chaos in Kyoto and the breakdown of bakufu power the samurai magnates of the provinces and the jizamurai seized power and set themselves up as independent lords becoming daimyo ('great names'.) The old shugo, the provincial officials subject to the shogun, were no more. The peasants themselves capitalised on the Onin War and none more so than in Kaga Province which was ruled by the Togashi family, a powerful samurai clan. In 1488 the Ikko-ikki ('single-minded league'), a league formed from mostly the lower sections of society, aided the people of Kaga Province to overthrow their rulers and set up government there. This was the first time that neither courtiers or samurai had rulership of a province but they did not stop there. They spread out from Kaga to Nagashima and Ishiyama Honganji (this great fortress, where Osaka now stands, did not fall until 1580 when Oda Nobunaga conquered it.) By now the Sengoku-Jidai (a term derived from the Warring States period in ancient China) or Age of Warring States was underway and the scene was set for the mighty to overcome the weak and vie for control of Japan itself.

Further Reading

The Samurai - Anthony J Bryant.

Samurai Commanders (1) - Stephen Turnbull.

Warriors of Medieval Japan - Stephen Turnbull.