Probably because of this cavalier treatment, Sadatsugu had been bearing a grudge against Hideyoshi; at the Battle of Sekigahara in 1600, he sided with the Eastern Army (the enemy of the Toyotomi family) and obtained military achievements; after the war, he was allowed to maintain his domain and set up Ueno Domain in Iga Province.
定次はこの秀吉の仕打ちを恨んだのか、1600年の関ヶ原の戦いでは東軍に与して武功を挙げたことから所領を安堵され、伊賀上野藩を立藩した。