Battle of Guinegate
1479 CE.
Shown on the map at 50.608°, 2.271°.
The First Battle of Guinegate took place on 7 August 1479. King Louis XI's French troops, led by Philippe de Crèvecœur d'Esquerdes (who had been a commander under Charles the Bold but defected to the French side after the latter's death in 1477), were defeated by the Burgundians, led by Duke (later Emperor) Maximilian I of Habsburg. The battle was the first in which the innovative Swiss pike square formation was used by a power that was not natively Swiss.
Text from the Wikipedia article Battle of Guinegate (1479), licensed CC BY-SA 4.0.