Battle of Montiel
1369 CE.
Shown on the map at 39.000°, -4.000°.
The Battle of Montiel was fought on 14 March 1369 between the Franco-Castilian forces supporting Henry of Trastámara and the Granadian-Castilian forces supporting the reigning Peter of Castile.
Text from the Wikipedia article Battle of Montiel, licensed CC BY-SA 4.0.