When war was declared the Staff of the Irish Command became automatically the staff of the II Army Corps and accordingly with the outbreak of the First World War in August 1914, he was promoted brigadier general, and as part of the British Expeditionary Force in France took charge of the Adjutant and Quartermaster-General's Department during the retreat of the 2nd Corps after the Battle of Mons, to Paris, and during the Battle of the Marne. In the middle of September 1914, he relieved one of the brigadiers in the fighting line as commander of the 13th Brigade (5th Infantry Division) and then commanded the 53rd Brigade (18th Infantry Division) till December 1915, when he was ordered home to assume command of the 16th (Irish) Division at Blackburn.