Battle of Bạch Đằng
981 CE.
Shown on the map at 20.990°, 106.755°.
The Song–Đại Cồ Việt war was a military conflict between the Song dynasty and Đại Cồ Việt in 981. It resulted in a victory for Đại Cồ Việt over the Song forces.
Text from the Wikipedia article Song–Đại Cồ Việt war, licensed CC BY-SA 4.0.