Ōnin War The was a civil war that lasted 10 years ( 1467 – 1477 ) during the Muromachi period in Japan . A dispute between Hosokawa Katsumoto and Yamana Sōzen escalated into a nationwide war involving the Ashikaga shogunate and a number of daimyo in many regions of Japan . The war initiated the Sengoku jidai , " the Warring States Period " . This period was a long , drawn - out struggle for domination by individual daimyo , resulting in a mass power - struggle between the various houses to dominate the whole of Japan . During this long period three individuals emerged who would unite Japan under one rule ; they were Oda Nobunaga , Toyotomi Hideyoshi , and Tokugawa Ieyasu . Origin . The " Ōnin " conflict began as a controversy over who would become shogun after the retirement or death of Shogun Ashikaga Yoshimasa . In 1464 , Yoshimasa had no heir . He persuaded his younger brother , Ashikaga Yoshimi , to abandon the life of a monk , and Yoshimi was named heir . In 1465 , the unanticipated birth of a son to Yoshimasa put these plans in question . The infant , Yoshihisa , caused friction between the two brothers . Hosokawa had always worked closely with the Shogun ' s brother Ashikaga Yoshimi , and supported his claim to the shogunate . Yamana took this as an opportunity to oppose Hosokawa further , supporting the child as heir to the Shogunate . War broke out in the city of Heian - kyō ( Kyoto ) . This was regarded by the Ashikaga Shogun as an act of rebellion , and thus the Ashikaga and their supporters were forced to try to stop it . The Ashikaga tried to prevent the outbreak of war over the next heir , but the situation escalated into a war that designated the leader of the victorious party as the next shogun . In 1467 the uncertainty had caused a split amongst the warrior clans ; and the succession dispute became a pretext for a struggle for military supremacy . In the end , there was no clear - cut winner . The complex array of factional armies simply fought themselves into exhaustion . Battles . By July 1467 the fighting had become serious , and this was when the Ōnin War is said to have started . By September , Kyoto ' s northern parts were in ruins , and everyone who could flee from Kyoto did so . Both Yamana Sōzen and Hosokawa Katsumoto died in 1473 , and even then , the war continued on , neither side figuring out how to end the war . However , eventually the Yamana clan lost heart as the label of " rebel " was at last having some effect . Ōuchi Masahiro , one of the Yamana generals , eventually burnt down his section of Kyoto and left the area . By 1477 , ten years after the fighting had begun , Kyoto was nothing more than a place for mobs to loot and move in to take what was left . Neither the Yamana clan nor the Hosokawa clan had achieved its aims , other than to whittle down the numbers of the opposing clan . During this whole ordeal , the shogun was not instrumental in alleviating the situation . While Kyoto was burning , Ashikaga Yoshimasa spent his time in poetry readings and other cultural activities , and in planning Ginkaku - ji , a Silver Pavilion to rival Kinkaku - ji , the Golden Pavilion that his grandfather , Ashikaga Yoshimitsu , had built . The Ōnin War , and the shogun ’ s complacent attitude towards it , " sanctioned " private wars and skirmishes between the other daimyo . No part of Japan escaped the violence . Although the battles in Kyoto had been abandoned , the war had spread to the rest of Japan . In Yamashiro Province , the Hatakeyama clan had split into two parts that fought each other to a standstill . This stalemate was to have serious consequences . In 1485 , the peasantry and ji - samurai ( lesser samurai - mostly armed peasants ) had had enough , and revolted . Setting up their own army ( the ' Ikki ' ) , they forced the clan armies to leave the province . The Ikki became a powerful force , much more than simply an armed mob . By 1486 they had even set up a provisional government for Yamashiro province . The Ikki would form and appear throughout other parts of Japan , such as Kaga Province , where a sect of the Jodo Shinshu Buddhists , the Ikkō , started their own revolt during the Ōnin War after being enlisted by one of Kaga ' s most prominent warlords , Togashi Masachika . The Ikkō , who had a complex relationship with the Jodo Shinshu leader Rennyo , appealed to the common peasants in their region , and inevitably formed the Ikkō - ikki . By 1488 the Ikkō - ikki of Kaga Province expelled Masachika and the other warlords , and took control of the province . After this they began building a fortified castle - cathedral along the Yodo River and used it as their headquarters . The Ikkō - ikki and the Yamashiro - ikki were revolutionary , in a process called " gekokujō " ( " the low oppress the high " ) . Aftermath . After the Ōnin War , the Ashikaga " bakufu " completely fell apart ; for all practical purposes , the Hosokawa family was in charge and the Ashikaga shoguns became their puppets . When Yoshimi ' s son Yoshitane was made shogun in 1490 , the Hosokawa Kanrei ( deputy ) soon put him to flight in 1493 and declared another Ashikaga , Yoshizumi , to be shogun . In 1499 , Yoshitane arrived at Yamaguchi , the capital of the Ōuchi , and this powerful family threw its military support behind Yoshitane . In 1507 , the Kanrei Hosokawa Masamoto was assassinated and in 1508 , Yoshizumi left Kyoto and the Ōuchi restored the shogunate to Yoshitane . Thence began a series of strange conflicts over control of the puppet government of the shogunate . After the death of Hosokawa Matsumoto , his adopted sons Takakuni and Sumimoto began to fight over the succession to the Kanrei , but Sumimoto himself was a puppet of one of his vassals . This would characterize the wars following the Ōnin War ; these wars were more about control over puppet governments than they were about high ideals or simply greed for territory . The Hosokawa family would control the shogunate until 1558 when they were betrayed by a vassal family , the Miyoshi . The powerful Ōuchi were also destroyed by a vassal , Mōri Motonari , in 1551 ; by the end of the Warring States Period only a dozen or so warlord families still remained standing . But the most important development to come out of the Ōnin War was the ceaseless civil war that ignited outside the capital city . Hosokawa tried to foment civil strife in the Ōuchi domains , for instance , and this civil strife would eventually force Ōuchi to submit and leave . From the close of the Ōnin War , this type of civil strife , either vassals striving to conquer their daimyo or succession disputes drawing in outside daimyo , was endemic all throughout Japan . Scholars disagree on the appropriateness of the term " Warring States period " ( which is the Chinese term borrowed by the Japanese in calling this period " sengoku jidai " ) . Many argue that since Japan was essentially intact , the Emperor and shogunate remaining at least nominally in command of the whole country , it really wasn ' t a " warring states " period at all , but a " warring warlords " period . However , others such as Mark Ravina , Mary Elizabeth Berry , and Conrad Totman argue that the " kuni " ( provinces ) were not unlike quasi - independent states , and that the term is thus more or less appropriate . The cost for the individual daimyo was tremendous , and a century of conflict would so weaken the bulk of Japanese warlords , that the three great figures of Japanese unification , beginning with Oda Nobunaga , would find it easier to militarily assert a single , unified military government . Kyoto . Kyoto was devastated by the war , not really recovering until the mid - 16th century . The city has not seen such widespread destruction since , being spared the strategic bombing of Japanese cities during World War II . In Kyoto , " pre - war " refers to the Ōnin War , rather than WWII . " Ōnin Ki " . The " Ōnin Ki " ( 応仁記 ) is a document written sometime from the end of the 15th century to the middle of the 16th century ( i . e . some 20 to 80 years after the conflict ) , which describes the causes and effects of the " Ōnin " War . It illustrates in detail the strategies involved in the fighting , and its chief instigators , Yamana Sōzen and Hosokawa Katsumoto . Though it is classified as a work of historical military fiction ( 軍記物語 ) , because of the time in which it was written , it is entirely possible that the author is relating a first person account of the conflagration . Though its author is unknown , his beliefs and philosophies are apparent throughout the text , as he relates the apparent futility of the war and the destruction it wrought on the capital . It remains an important work in part due to its departure from somewhat cut - and - dry depictions of the numerous battles , instead adding accounts of how the Onin War affected the city and its citizens : " The capital which we believed would flourish for ten thousand years has now become a lair for the wolves . Even the North Field of Toji has fallen to ash . . . Lamenting the plight of the many fallen acolytes , Ii - o Hikorokusaemon - No - Jou read a passage : ' Now the city that you know Has become an empty field , From which the skylark rises And your tears fall . ' " Chronology ( III Trey , Michael ) . The origins of the " Ōnin " conflict are manifold . To say that the war began with a quarrel between angry warlords is too simplistic . The initial phase of this decade - long struggle was only a spark which set fire to a broader conflagration . Without fully anticipating the consequences , the Kamakura government had loosened the restraints of tradition in Japanese society , which meant that new energies were released , new classes were formed , and new wealth was created . As the shogunate ' s powerful figures competed for influence in Kyoto , the leading families in the provinces were amassing resources and growing more independent of centralized controls . Precursors Warfare begins Sequelae