After the Battle of Sekigahara, Masamune DATE reluctantly returned to the Iwatesan-jo Castle because he was ordered by Ieyasu TOKUGAWA not to move his troops without permission, but he invaded the Fukushima-jo Castle held by Shigenaga HONJO on October 6, 1600 without waiting for command from Ieyasu because it was hard for him to give up the invasion to the Uesugi's territory.
関ヶ原合戦後、伊達政宗は徳川家康からみだりに軍勢を動かすべからずとの命を受け、心ならずも岩手山城へ引き返したが、上杉領への侵略やみがたく、家康の下知をまたずに慶長5年10月6日、本庄繁長が立て籠もる福島城へ押し寄せた。