In April 1584, Nobukatsu killed his three key retainers, i.e., Yoshifuyu TSUGAWA, Shigetaka OKADA, and Nagatoki AZAI, based on the reason that they were in secret communication with Hideyoshi, and asked Ieyasu TOKUGAWA for help, which resulted in the Battles of Komaki and Nagakute.
そして天正12年（1584年）3月、秀吉に内通したという理由で重臣の津川義冬・岡田重孝・浅井長時ら3人を殺害し、徳川家康に助けを求めたことから小牧・長久手の戦いが起きる。