Siege of Calais
1436 CE.
Shown on the map at 50.947°, 1.856°.
The siege of Calais between June and July 1436 was a failed siege of English-held Calais by Philip the Good, Duke of Burgundy, and Flemish militia.
Text from the Wikipedia article Siege of Calais (1436), licensed CC BY-SA 4.0.