sistance as they slowly advanced on Verdun and its forts. Sporadic French resistance was encountered. The Germans took Fort Douaumont and then reinforcements halted the German advance by 28 February. The Germans turned their focus to Le Mort Homme on the west bank of the Meuse which blocked the route to French artillery emplacements, from which the French fired across the river. After some of the most intense fighting of the campaign, the hill was taken by the Germans in late May. After a change in French command at Verdun from the defensive-minded Philippe Pétain to the offensive-minded Robert Nivelle, the French attempted to re-capture Fort Douaumont on 22 May but were easily repulsed. The Germans captured Fort Vaux on 7 June and with the aid of diphosgene gas, came within 1 kilometre (1,100 yd) of the last ridge before Verdun before being contained on 23 June. Over the summer, the French slowly advanced. With the development of the rolling barrage, the French recaptured Fort Vaux in November and by December 1916 they had pushed the Germans back 2.1 kilometres (1.3 mi) from Fort Douaumont, in the process rotating 42 divisions through the battle. The Battle of Verdun—also known as the 'Mincing Machine of Verdun' or 'Meuse Mill'—became a symbol of French determinati