However the prestige of Hindenburg and Ludendorff meant that the German effort for 1915 was concentrated in the east. He ordered the Second Battle of Ypres (22 April-25 May 1915) to hid the movement of German troops to the east. This battle saw the first use of poisoned gas, but Falkenhayn had no faith in the new weapon, and missed the chance for a real breakthrough. Hindenburg's attack in the east saw great successes, but did not bring victory over Russian any nearer. Meanwhile, Falkenhayn's prestige was enhanced by the success of his plan to crush Serbia, which fell to a combined Austrian, German and Bulgarian offensive in October-November 1915, and he was able to persuade the Kaiser to make the Western Front the focus for 1916. He picked the historic city of Verdun for his strike, suspecting that French resistance would fail if Verdun fell, and that he could bleed the French dry if it did not. At the time it was at the centre of a salient reaching into the German lines.
On 21 February 1916 he launched the battle of Verdun (to 18 December 1916), and for some time it looked as if he would be successful, but the battle soon bogged down, and by April he was ready to stop the battle, but his subordinates were unwilling to abandon land over which so much blood had been spilt. The failure at Verdun started to weaken his position. He was further compromised by heavy losses suffered during counterattacks he ordered during the battle of the Somme (24 June-13 November 1916), and on 29 August 1916 he was replaced by Hindenburg and sent to deal with Romania, recently entered into the war on the allied side. In command of the German Ninth Army, he played an important part in the quick German victory over Romania, which saw her occupied by the end of the year. Towards the end of 1917 he was sent to take command of the Palestine front, arriving in Jerusalem on 1 November 1917, too late to make a difference, and the city fell to the British on 9 December 1917. He was replaced by General Liman von Sanders on 25 February 1918, and placed in charge of the German Tenth Army in Lithuania (5 March 1918), by now not a combat command. He retired in 1918, and died in 1922. As Chief of the General Staff he had only rarely been able to have things entirely his own way, but he was an able general.