Sanada clan
During the Sengoku period, the area around Ueda was under the control of the Sanada clan, a minor local warlord in the service of the Takeda clan. After the fall of the Takeda clan to the combined forces of Oda Nobunaga and Tokugawa Ieyasu, the Sanada switched side with bewildering rapidity between the Uesugi clan, the Hōjō clan, Oda Nobunaga and Toyotomi Hideyoshi in an effort to preserve their territory and independence. Ueda Castle was constructed in 1583 by Sanada Masayuki with the assistance of his then-ally, Tokugawa Ieyasu as a stronghold against Uesugi Kagekatsu; however it came under attack by the Tokugawa in 1585 after Masayuki switched sides again join the Uesugi. The greatly outnumbered Sanada defeated the forces of Tokugawa Ieyasu in the Battle at Kami River, which greatly enhanced Sanada Masayuki’s reputation.