Massacre of Mérindol
1545 CE.
Shown on the map at 43.757°, 5.204°.
The Mérindol massacre took place in 1545, when Francis I of France ordered that the Vaudois (Waldensians) of the village of Mérindol be punished for heresy. Provençal and papal soldiers killed hundreds or even thousands of Waldensian villagers.
Text from the Wikipedia article Mérindol massacre, licensed CC BY-SA 4.0.