5927134 Major William Leith-Ross on his horse at Sar-i-Mil, India, 1920 (b/w photo) by Unknown photographer, (20th century); National Army Museum, London; (add.info.: Major William Leith-Ross on his horse at Sar-i-Mil, India, 1920. Photograph, India, North West Frontier, 1920. During World War One (1914-1918) Leith-Ross served with 57th Wilde\'s Rifles (Frontier Force) as a company commander and then a staff officer at the Ferozepore Brigade headquarters. He was present at La Bassee (1914), Messines (1914), Givenchy (1914), Neuve Chapelle (1915) and the Second Battle of Ypres (1915). In 1916 he was attached to the intelligence staff of the Indian Expeditionary Force?s headquarters in Mesopotamia. Throughout 1916 and 1917 he travelled by motor vehicle and aircraft to reconnoitre, photograph, survey and report on the British area of operations. From January to September 1918 he was seconded to Dunsterforce, the British Military Mission to the Caucasus. After this, Leith-Ross continued to serve in Mesopotamia until late 1919. During the early 1920s he attended the Indian Army Staff College at Quetta before undertaking staff and regimental appointments. Between 1929 and 1932 he commanded 5th Battalion, 13th Frontier Force Rifles, leading it during several frontier operations. From an album of 334 photographs compiled by Maj W Leith-Ross, Army Staff and 13th Frontier Force Rifles, 1918-1920.); by National Army Museum .