During the First World War Mangin rose from divisional command to that of the Tenth Army for the Second Battle of the Marne, commanding both French and American troops. Nicknamed "the Butcher" for his espousal of "la guerre à outrance" (all-out war) and his faith in the suitability of North African Tirailleur for the attack, there was no doubt in the French Army that Mangin was fearless. Unlike many French generals who did not visit the front, Mangin was shot in the chest while exhorting his men for further attacks during the Second Battle of Champagne, though he returned to duty ten days later. During that war, Mangin had notable victories at the Battle of Charleroi in 1914 and then at the Battle of Verdun in 1916 but his reputation suffered following the disastrous Nivelle Offensive (16 April – 9 May 1917). This was due partly to the fact that Mangin was one of the few high-ranking French officials who supported Nivelle's strategy.