After Hideyoshi passed away, Shigekatsu stood by the side of Mitsunari ISHIDA during Ieyasu TOKUGAWA's conflict with Mitsunari; in 1600, he attacked and conquered Tanabe-jo Castle protected by Yusai HOSOKAWA who stood at Ieyasu's side (the Battle of Tanabe-jo Castle).
重勝は秀吉の没後、徳川家康と石田三成とが対立すると三成に味方し、1600年（慶長5年）には家康方の細川幽斎が守る田辺城を攻め落城させた（田辺城の戦い）。