Battle of Poimanenon
1224 CE.
Shown on the map at 37.892°, 36.000°.
The Battle of Poimanenon or Poemanenum was fought in early 1224 (or possibly late 1223) between the forces of the two main successor states of the Byzantine Empire; the Latin Empire and the Byzantine Greek Empire of Nicaea. The opposing forces met at Poimanenon, south of Cyzicus in Mysia, near Lake Kuş.
Text from the Wikipedia article Battle of Poimanenon, licensed CC BY-SA 4.0.