Battle of Sunomata-gawa
1181 CE.
Shown on the map at 35.353°, 136.684°.
The Battle of Sunomata-gawa (墨俣川の戦い, Sunomata-gawa no Tatakai) took place in Japan on 6 June 1181 (or by the Japanese calendar, Jishō-5 year, 4-month, 25-day), in the present-day town of Sunomata, Gifu Prefecture. The battle started when Minamoto no Yukiie attempted a sneak attack across the Sunomata River against his enemies during the night. He found Taira no Tomomori and his army directly opposite his, along the Sunomata River, near the borders of Owari and Mino provinces. The Minamoto warriors waded across, but their ambush failed when the Taira clan could distinguish dry friend from soaking, dripping wet foe, even in the pitch dark of night. Yukiie and a number of other surviving Minamoto were forced back across the river. After crossing the river, the Minamoto went to the Yahagi River in Mikawa Province, but the Taira chased after them.
Text from the Wikipedia article Battle of Sunomata-gawa, licensed CC BY-SA 4.0.