In 1600, after Ieyasu TOKUGAWA and his allies moved their troops to defeat Kagekatsu UESUGI of Aizu, Mitsunari ISHIDA and his allies denounced Ieyasu and moved their troops (the West) against him and thus the Battle of Sekigahara began.
慶長5年（1600年）、徳川家康らが会津の上杉景勝討伐のため東へ向かうと石田三成らが家康の非を鳴らして挙兵し（西軍）、関ヶ原の戦いが起こった。