小牧・長久手の戦い
In 1584, Tokugawa Ieyasu lead his army west towards Owari province in the Battle of Komaki and Nagakute against Hashiba Hideyoshi. Masayuki was left in northern Shinano to keep the Uesugi clan in check and took this opportunity to subjugate small, neighboring landlords and consolidate his power in the region. In December, as Ieyasu made peace with Hideyoshi and returned to his territory, he was pressed by Hōjō Ujinao to act on the terms of their treaty.