with Major-General Hugh Elles inspecting tanks and crews at Sautricourt, 10 August 1918. On the outbreak of the
First World War in August 1914, he was posted to the staff of the
4th Division and departed for France soon afterwards. He served at
Le Cateau, then took part in the
Retreat to the Seine and the
battle of the Aisne, where the
Imperial German Army was halted. He then moved north with the
British Expeditionary Force to
Flanders, taking part in the
Battle of Armentières in October 1914. In February 1915, he was promoted to
brevet major and the next month became the
brigade major of the
10th Infantry Brigade. He was wounded during the brigades'
counterattack, on 25 April 1915, during the
Second Battle of Ypres. In August 1915, after recovering from his injuries, Elles was one of three officers specially selected by
General Sir William Robertson, soon to be
Chief of the Imperial General Staff (CIGS), the professional head of the British Army, to liaise with troops at the front and pass the information directly to the British General Headquarters (GHQ). He was promoted to major in November 1915. In January 1916, as a
general staff officer (GSO), Elles was sent by General
Sir Douglas Haig, the
commander-in-chief of the BEF on the
Western Front, to investigate the first
tanks or "caterpillars" being built in England. He attended the first trials of
"Mother" and reported back to Haig on its success. During the summer of 1916, Elles, who in June had been awarded the
Distinguished Service Order (DSO), was tasked to report back from the
Somme, where the tanks were first used. He was made a general staff officer, grade 1 in June 1916 and was granted the temporary rank of lieutenant colonel while holding the appointment. Promoted to the temporary rank of
colonel, Elles was appointed to head the Heavy Branch (the first tank units) of the
Machine Gun Corps in France on 29 September 1916. Elles, promoted to brevet colonel in June 1918, continued to command the Tank Corps until
Germany's surrender in November 1918. For his services during the war he was awarded the
Army Distinguished Service Medal by the
Government of the United States. The citation for the medal reads: ==Later career==