On the outbreak of the First World War, he initially served in the War Office, and in November 1914 he was promoted to Brigadier-General in command of the 115th Brigade. In January 1916 he took command of the 38th (Welsh) Infantry Division, bringing the division to France, and after a break while he held ministerial office in London he led the division during the first assault on Mametz Wood, at the Battle of the Somme in 1916.