425 years ago today, on October 21, 1600 (September 15, 1600, the 1600 lunar calendar), the Battle of Sekihara broke out in Japan. On October 21, 1600, the Battle of Sekihara broke out in Japan. The Western Army led by Sansei Ishida and the Eastern Army led by Tokugawa Ieyasu (about 80,000 people on both sides) set up a battlefield in Sekihara near Gifu. During the fierce battle between the two sides, Hideaki Koyakawa, who was originally part of the Western Army, led 15,000 troops under his command to suddenly defect, triggering a chain reaction of many Western generals defecting, resulting in the complete defeat of the Western Army. The main generals of the Western Army, Yoshiki Otani and Shimashima, were killed one after another. More than 40,000 people were killed in the Western Army. Sansei Ishida and others were arrested and beheaded. This battle determined Japan's historical trend, and Tokugawa Ieyasu gained control over all of Japan after Toyotomi Hideyoshi. Comment: The Tokugawa family began its shogunate rule that lasted for nearly 300 years