The Onin War (Onin no Jidai)
by Joshua Gilbert
The Onin War, (so called because it occurred in the regnal year Onin 1), was
the catalyst that sparked the century long period of Japanese history known as
the Sengoku Jidai, the "Age of the Country at War". What began originally as a
dispute between a father and his son-in-law, became an eleven year war that
trashed the once great city of Kyoto and sparked an era of bloodshed that
remains famous to this day.
The Onin War began because of the weakness of one Shogun. In 1464, Ashikaga
Yoshimasa, the 8th member of the Ashikaga clan to hold the title
Seii-Taishogun, and a man renowned for his focus on tea parties and poetry,
wanted to retire but had no son. He decided to instead make his younger
brother, Yoshimi, his heir. However Yoshimi was a Buddhist monk, so the Shogun
had to first drag his brother out of the monastery in order to make him his
But one year later in 1465, his wife Tomiko, bore him a son. Overjoyed, the
Shogun made his infant son Yoshihisa his heir instead. At the same time two of
the most powerful men in Kyoto which was the capital at the time, were in the
midst of a feud. On one side there was Yamana Sozen, nicknamed Red Monk, a
Buddhist monk who was famous for turning red when angry. On the other side was
his son-in-law Hosokawa Katsumoto, one of the Three Butlers of the Ashikaga
clan (the other two were the Shiba and Hatakeyama clans).
These two men had been engaged in a feud since the 1450s after they had meddled
in the succession disputes of the Hatakeyama and Shiba families. Now they had
another dispute in which to outmaneuver each other, this time involving the
highest office in Japan. This was the leading cause of the war to come. Sozen
acted first by declaring his backing for the infant Yoshihisa. Katsumoto threw
his backing behind the Shogun's brother, Yoshimi. Both men summoned support
from family relations and vassals, and soon the entire capital district of
Yamashiro was chocked with Yamana and Hosokawa supporters. The armies numbered
80,000 and 85,000 respectively, the largest yet seen in Japanese history. Yet
both men were reluctant to dive into a war. In 1467 Yamana Sozen called in the
powerful warlord Ouchi Masahiro with another 20,000 troops. Then in February, a
Hosokawa mansion "mysteriously" went up in flames. The war was on.
The Onin War, had begun. The Hosokawa retaliated for the destruction of their
mansion in April when samurai, loyal to them, attacked a Yamana rice shipment.
In May rumors abounded that Yamana Sozen was going to attack the Imperial
Palace. Hosokawa Katsumoto decided to act regardless of the truthfulness of
these rumors and moved Emperor Go-Tsuchimikado, Retired Emperor Go-Hanazono,
and the entire Imperial family out of the Palace to the headquarters of the
Shogunate in Muromachi District. As it turned out Hosokawa had made the right
for Yamana did launch an attack on the Imperial Palace .
At the end of the month, Hosokawa supporters burned the mansion of Yamana
general Isshiki, along with the entire block to the ground. The Yamana
counterattack was fierce, and the war, which until this point had been merely a
series of raid and counter raid, now intensified into a full-fledged war in the
streets. By July the fighting was so devastating that all of northern Kyoto was
in ruins and the remainder of the city resembled the battlefields of the
centuries later First World War in Europe. The battle for Shokokuji in October,
in which Yamana Sozen himself led an attack on the Hosokawa positions inside a
Buddhist monastery, exemplified the carnage. There were enough enemy heads to
fill eight carts. By September anyone who could abandon the city did so, even
while more reinforcements for the warring factions flowed in.
By early 1468, a calm came over Kyoto. Both sides rested but kept watch each
other from across their respective trenches. Hosokawa then resumed hostilities,
bringing in trebuchets and using them to fling rocks and exploding bombs into
Yamana territory. Sometime later Hosokawa Katsumoto scored a major political
coup when he was able to convince both Shogun Ashikaga Yoshimasa and the
Emperor to denounce the Yamana as rebels. With the official backing of both
Shogun and the Emperor, the Hosokawa now held the moral high ground in the
conflict. Any who supported Yamana Sozen did so at the danger of being declared
a traitor to the Emperor.
At first, Yamana Sozen treated his branding with indifference. He had the
support of such men as Ouchi Masahiro and several great clans as well and he
would be able to get the ruling reversed later. Carnage and destruction
continued for several years without any sign of letting up. Even the deaths of
Hosokawa Katsumoto and Yamana Sozen had little effect on the war.
What had started as a personal spat had spiraled beyond all control. In 1475
Ashikaga Yoshimasa, previously caught up in his little world of poetry and tea,
asserted some authority and began to order the various shugo daimyo, (feudal
lords who acted as deputies for the Shogun), on both sides, out of Kyoto. Many
shugo obeyed the Shogun and began to disengage. However the fighting would
continue until 1477, as some stubbornly refused to give up. Ouchi Masahiro, the
great champion of Ashikaga Yoshihisa's cause, finally brought the war to a
close when he too finally agreed to the Shogun's will and left for home in
Yamaguchi. As one last act of defiance he burned his section of Kyoto, the last
one reasonably intact, to the ground as he left, later blaming it on his common
soldiers. With the pull out of the Ouchi and their vassals from the conflict
the eleven year long Onin War ended, not because one side achieved victory, but
because both sides simply did not have the strength to continue anymore.
But much more happened in the aftermath of the war. Ashikaga Yoshimasa did
little to help as he slid once more back into his private world. With the
departure of the last soldiers, mobs descended on the city It would be several
years before peace was restored. The chaos in Kyoto had a much larger effect
than expected as the fires of war spread into the countryside. Villages banded
together under the Ji-Samurai (lesser samurai with common roots), forming armed
bands called Ikki which soon mutated from mobs of peasants into disciplined
armies. The rise of the Ikki and the continued chaos in Yamashiro (the
Hatakeyama clan tore the province apart in a family feud) would soon prove to
be just the beginning of one Japan's bloodiest periods. The century long
Sengoku Jidai had begun.
Copyright © 2007 Joshua Gilbert
Written by Joshua Gilbert. If you have questions or comments on this
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Published online: 02/11/2007.
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