As a protégé of General Henry Wilson, he held important staff positions at the War Office before the war and at British Expeditionary Force (BEF) GHQ in 1914. He later commanded the 51st (Highland) Division at the Battles of the Ancre, Arras, Third Ypres and Cambrai. It was widely claimed by tank officers that his adoption of idiosyncratic tactics at Cambrai caused his division's failure to reach its objectives, although this view has now been called into question. He commanded IV Corps in 1918.