上田城
However, under Toyotomi Hideyoshi, the Sanada were forced to submit fealty to Tokugawa Ieyasu and Sanada Masayuki's first son, Sanada Nobuyuki, was married to Komatsuhime, an adopted daughter of Ieyasu; while his second son, Sanada Yukimura (Nobushige), was married to Chikurin-in, an adopted daughter of Hideyoshi. After the death of Hideyoshi, the Tokugawa ordered the Sanada to participate in their invasion of Aizu against the Uesugi clan. Sanada Nobuyuki chose to remain on the Tokugawa side, while Sanada Masayuki and his younger son, Sanada Yukimura chose to join the Toyotomi armies under Ishida Mitsunari against the Tokugawa. This led to the Siege of Ueda in 1600, a side battle to the Battle of Sekigahara. The army of Tokugawa Hidetada, while on their way to Sekigahara was ordered to reduce Ueda Castle along the away. Again, the greatly outnumbered Sanada forces inflicted severe casualties on the Tokugawa and delayed Hidetada so long that he was forced to break off the siege and his forces thus arrived at Sekigahara too late to make a contribution to the battle.