Battle of Mikatagahara
1573 CE.
Shown on the map at 34.794°, 137.702°.
The Battle of Mikatagahara (三方ヶ原の戦い, Mikatagahara no tatakai) took place during the Sengoku period of Japan between Takeda Shingen and Tokugawa Ieyasu in Tōtōmi Province on January 25, 1573. Shingen attacked Ieyasu on the plain of Mikatagahara north of Hamamatsu during his campaign against Oda Nobunaga while seeking a route from Kōfu to Kyoto. The Tokugawa-Oda force was almost totally annihilated by the Takeda after being encircled and many of Ieyasu's retainers were killed in the battle. Ieyasu and his surviving men were forced to retreat before launching a minor counterattack to delay Shingen's march towards Kyoto.
Text from the Wikipedia article Battle of Mikatagahara, licensed CC BY-SA 4.0.