Toyotomi Hideyoshi and Tokugawa Ieyasu sent a large army into the Tōhoku region in mid-1591 which quickly defeated the rebels and Hideyoshi's army arrived at Kunohe Castle in early September.
This passage describes the swift defeat of rebels by Toyotomi Hideyoshi and Tokugawa Ieyasu, who then arrived at Kunohe Castle in early September after their successful campaign.