Battle of Ravenna
729 CE.
Shown on the map at 44.417°, 12.200°.
The Battle of Ravenna in 729 was fought between the troops of the Eastern Roman (Byzantine) Exarchate of Ravenna and a force of Lombard Italians. This was in response to Emperor Leo III the Isaurian outlawing the veneration of holy icons, which Pope Gregory II was against. After a fierce battle, the Eastern Roman Army was overcome and thousands of Byzantines were killed.
Text from the Wikipedia article Battle of Ravenna (729), licensed CC BY-SA 4.0.