Battle of Olivento
1041 CE.
Shown on the map at 41.051°, 15.753°.
The Battle of Olivento was fought on 17 March 1041 between the Byzantine Empire and the Normans of southern Italy and their Lombard allies near the Olivento river, between the actual Basilicata and Apulia, southern Italy.
Text from the Wikipedia article Battle of Olivento, licensed CC BY-SA 4.0.