Battle of Anegawa
1570 CE.
Shown on the map at 35.416°, 136.322°.
The Sengoku period Battle of Anegawa (姉川の戦い, Anegawa no Tatakai) (30 July 1570) occurred near Lake Biwa in Ōmi Province, Japan, between the allied forces of Oda Nobunaga and Tokugawa Ieyasu, against the combined forces of the Azai and Asakura clans. It is notable as the first battle that involved the alliance between Nobunaga and Ieyasu, and it saw Nobunaga's prodigious use of firearms.
Text from the Wikipedia article Battle of Anegawa, licensed CC BY-SA 4.0.