The terrible Battle of the Donon, which took place on August 20 and 21, 1914, marked the beginning of the French retreat. During the twelve-hour battle, marked by intense artillery fire and bayonet charges, between 500 and 2,000 dead lay on the slopes of the Donon. In 1916, German authorities erected some 180 stelae of pink sandstone to replace the wooden crosses erected in 1914 and engraved to commemorate the French and German soldiers who lost their lives here. The Petit Donon, once a battlefield, became an open-air necropolis for soldiers from both sides.