Bauer strongly opposed Falkenhayn's plan to attack Verdun in 1916 along a narrow front on the right bank of the Meuse, because their flank would be vulnerable to French artillery on the left bankhe was spot-on; before long they had to attack the left bank as well. While arranging artillery support before the attack he stayed at Fifth Army headquarters where he became a fast friend of its commander, Crown Prince Wilhelm; they kept in touch thereafter. In the first salvo of the attack a 42 cm shell struck Fort Douaumont, a key to the defense. It did not penetrate the reinforced concrete and sand layers: the Verdun forts were stouter than any the mortars had fired on hitherto. Later that year Bauer was dismayed by Falkenhayn's insistence along the Somme front on packing infantry into the foremost trenches to repel the attacks, where they were chewed-up by the Entente's artillery preparations. Bauer decided that Falkenhayn must be replaced by his friend Ludendorff, who had displayed virtuosity on the Eastern Front. Supported by junior officers at OHL he tirelessly lobbied the highest echelons of the army and government against his superior, with criticisms of Falkenhayn like "...his decisions were half measures and he wavered even over these." Falkenhayn was replaced on 29 August 1916 by Field Marshal Paul von Hindenburg as Chief of Staff with First Quartermaster General Ludendorff as his associate. To Bauer this was his greatest victory.