Battle of Ciani
1015 CE.
Shown on the map at 51.950°, 13.644°.
The Battle of Ciani was fought in July 1015 during the German–Polish War, between the army the Holy Roman Empire led by Henry II against the forces of Duchy of Poland. It was fought near the gord of Ciani (now Zützen, Germany). It was won by the German forces.
Text from the Wikipedia article Battle of Ciani, licensed CC BY-SA 4.0.