Right after the Honnoji Incident, it is often said that Ieyasu worked behind the scenes of Hidetaka KAWAJIRI's unusual death by a riot of a surviving retainer of the Takeda clan in Kai Province, and taking advantage of the death of Nobunaga, Ieyasu invading Kai and Shinano Provinces started a riot between the Hojo clan and the Uesugi clan who invaded the former territory of the Takeda clan with the same intention (Tenshojingo War).
本能寺の変の直後に甲斐において河尻秀隆が武田氏の遺臣の一揆により横死したのは家康が暗躍したためともいわれるが、信長の死に乗じて甲斐・信濃に侵攻し、おなじ意図をもって旧武田領に侵攻した北条、上杉とのあいだに騒乱を起こした（天正壬午の乱）。