Onin War in Japan

Onin War in Japan
Onin War in Japan

The Onin War came about directly as a result of the declining power of the Ashikaga Shogunate. The Ashikaga Shogunate, or military government, had been founded in 1336–37, by the astute Ashikaga Takauji.

Takauji had been sent by the Hojo shoguns to put down the rebellion of the emperor Go-Daigo. Go-Daigo was determined to throw off the rule of the military shoguns that had existed since the first true shogun, Minamoto Yoritimo, in 1192.

Go-Daigo’s first rebellion was in 1331 but was suppressed by the Hojo shogun Hojo Moritoki. When Go-Daigo rebelled a second time, Ashikaga Takauji was sent to lead the Hojo army against him. But Takauji switched sides and ensured Go-Daigo’s victory.

He accompanied Go-Daigo into the imperial capital of Kyoto. However, it was clear that he had only used Go-Daigo as a Trojan horse for his own ambitions and in 1337, Go-Daigo was forced to flee the capital as Ashikaga Takauji became shogun in his own right.

Although at first perceived as another military rule, the Ashikaga shoguns considered themselves true aristocrats of the Northern Court in Kyoto. Rather than the countrified shoguns at Kamakura, the Ashikagas considered themselves to be patrons of the arts.

The Ashikaga shoguns were such patrons of the arts that the style of the period derives its name from the Muromachi District in Kyoto where they established their mansion. They also patronized the o-chanoyu, the ceremony performed with Japanese green tea, which became a centerpiece in the life of any cultivated daimyo, or noble, family of the era.

With each generation the Ashikagas became more imperial courtiers and less military shoguns. The now courtly Ashikaga shoguns began to face challenges from another generation of countrified daimyo in the more remote provinces.

Increasingly the shogunate was unable to control these militaristic daimyo, and their failure to do so brought their demise. The climax came during the reign of the eighth Ashikaga shogun Yoshimasa, who began his rule in 1449. For all of his architectural and cultural accomplishments, Yoshimasa did little to strengthen the military of the shogunate.

The Onin War itself began as a struggle over who would lead two Echizen province daimyo families, the Hatekeyama and the Shiba clans. The Hatekeyama called on the mightier Yamana and Hosokawa clans.

The conflict ultimately drew in Yamana Sozen and Hosokawa Katsumoto, two far more powerful warrior daimyo. Yamana Sozen was known as the Red Monk, because he had taken a monk’s vows but still functioned as a warlord, as did Uesugi Kenshi, the great rival of Takeda Shingen.


Faced with what would prove to be a very bloody provincial struggle and unwilling to enter it, Ashikaga Yoshimasa announced in 1464 his intention to abdicate as shogun. Before he resigned he had to choose a successor in the Ashikaga Shogunate.

In one of the great ironies of Japanese history, his choice deprived him of the very life of peace he sought. He chose his brother, but his wife, Tomi-ko, wanted the next shogun to be their son. Tomi-ko secured the support of Yamana Sozen for her son’s candidacy, which inevitably brought Hosokawa Katsumoto to champion the cause of the emperor.

The Onin War, unlike other struggles, was to be fought out in the streets of the imperial capital of Kyoto. The main theater would be the stylish Muromachi District, which, since it served as the headquarters for Ashikaga rule, was where the families of the powerful daimyo had built their mansions to house them when business brought them to Kyoto.

By 1467 the Yamana and Hosokawa factions were waiting for the hostilities that both sides realized would soon begin. To his credit Yoshimasa remained shogun and tried to avert the breakout of war. He declared that whoever began the fighting would be branded a rebel, which meant execution and confiscation of all property.

In April 1467 fighting began when the first decisive move was struck by the Red Monk. To show his contempt for the emperor, he captured the imperial palace in Kyoto in one of his first attacks. But Yamana’s impetuous action backfired as he found it increasingly difficult to keep supporters.

In 1471 Yamana was so desperate that he attempted to revive the old Southern Court, but he could find no claimants to the throne, since the Ashikagas had influenced the members of the Southern Court to return to Kyoto in 1392 after the emperor abdicated.

Meanwhile the Hosokawas and the Yamanas attempted to gain strength from the countryside. Both sides received help from their retainers outside the capital, but none were able to gain military superiority in the battles that now raged in the capital city of Kyoto. As a result a bloody stalemate settled down in Kyoto, as the entire city was slowly devastated by the continual fighting.

The warring in Kyoto acquired a lethal momentum of its own. Even the deaths of both Yamana Sozen and Hosokawa Katsumoto in 1473 did not slow the bloodshed. Fighting spread to the provinces, where peasants staged ikko uprisings and provincial daimyo fought over land claims, knowing that the Ashikaga Shogunate was powerless to intervene in the growing anarchy.

The shogunate was still embroiled in the very succession crisis that had precipitated the Onin War. Yoshimasa finally gave in to his wife, Tomi-ko, in 1474, and appointed his son Yoshihisa to be his successor.

Ten years later, Yoshimasa finally achieved his dream of leaving the shogunate. Yoshihisa would rule until 1489. Nevertheless, the Onin War continued to devastate Kyoto.

In December 1477 Ouchi Masahiro, who had spent a decade fighting for the Yamanas, finally grew disgusted with the fighting and left the city, leaving the empty victory to the Hosokawas. The power of the Ashikaga Shogunate was effectively broken by the long conflict.

Although the family would continue to govern, the center of gravity decisively shifted to the daimyo in the provinces. In 1573 almost exactly a century after Yoshimasa abdicated, the daimyo Oda Nobunaga would depose the 15th Ashikaga shogun Yoshiaki, bringing the Ashikaga Shogunate to an end.