Ashikaga Yoshiaki became the 15th shogun of the Muromachi Shogunate, elevated to power by Oda Nobunaga's military might after Nobunaga seized Kyoto. His installation followed turmoil within the Ashikaga clan, including the assassination of his brother and predecessor, Shogun Yoshiteru.

Initially dependent on Nobunaga for authority, Yoshiaki offered him prestigious titles like deputy shogun or Kanrei in gratitude. Nobunaga refused these positions, signaling his disregard for formal shogunate roles and foreshadowing their future conflict.

Resentment grew as Yoshiaki perceived Nobunaga's dominance eroding his own power. The shogun's independent actions in Kyoto prompted Nobunaga to impose five strict rules, curtailing Yoshiaki's autonomy and solidifying Oda control over the unification campaign. These rules reduced the shogun to a figurehead under Nobunaga's de facto rule.

Yoshiaki's dissatisfaction erupted into open rebellion. He secretly conspired with rival daimyo, including the Asakura and Azai clans, seeking their military aid to overthrow Nobunaga and escape Oda influence. These covert alliances fueled conflicts challenging Oda forces, like the pivotal attack on Nobunaga during the Kanegasaki campaign.

Nobunaga responded decisively to the betrayal. His armies marched on Kyoto, deposed Yoshiaki, and forcibly expelled him from the capital in 1573. This expulsion ended the Ashikaga shogunate's effective power.

Exiled, Yoshiaki continued his resistance against Nobunaga. He retreated to western Japan, seeking sanctuary and support from powerful clans like the Mōri. From this refuge, he sustained his rallying cry against Nobunaga, participating in broader conflicts such as the Ishiyama Hongan-ji War, demonstrating his enduring struggle to regain political relevance despite lacking formal authority.