On 15 May 1915, after Bridges was mortally wounded by a sniper, an English officer, Brigadier General Harold Walker was given temporary command while a replacement was dispatched from Australia. This was Colonel James Legge, the Australian Chief of the General Staff, who was not an immediately popular choice with either his corps commander, Lieutenant General William Birdwood, or his subordinate brigade commanders. That same month, the division's artillery – three field artillery brigades each operating twelve 18-pound pieces, which had proved inadequate in the early battle, was boosted by the arrival of several Japanese-made trench mortars. They were later joined by several heavier guns including a 4.7-inch gun and two 6-inch howitzers. On 24 June, Legge replaced Walker, who returned to command of the 1st Brigade, but after Legge was evacuated from Gallipoli he was moved sideways to command of the newly formed Australian 2nd Division and Walker resumed command of the 1st Division.