[1] Having transferred to the 35th Scinde Horse, British Indian Army in 1886, he served in Waziristan on the North West Frontier of India in 1895 and was promoted to captain on 23 August 1895.

[2] He became aide-de-camp (ADC) to General Sir William Lockhart, Commander-in-Chief in India, in September 1899,[3] then served in China during the Boxer Rebellion the following year.

[1] In December 1901 he was appointed ADC to General Sir Arthur Palmer, who had succeeded as Commander-in-Chief in India,[4] and the following March he also tok the position of Interpreter to the C-in-C.[5] Promotion to major followed on 23 August 1902.

[1] He served in World War I as a staff officer, with the temporary rank of colonel, promoted to that rank in October 1914,[7] and to temporary brigadier general in the same month,[8] on British Expeditionary Force in 1914 and, promoted to temporary major general in August 1915,[9] as General Officer Commanding Yeomanry Mounted Division and the 4th Cavalry Division in 1917 and in 1918 being present at the fall of Jerusalem in Palestine in 1917.

[12] His father, Lyon de Symons Barrow (1823-1905) was a major-general in the service of the Indian Army then Inspector-General of Police in the United Provinces, and himself had several brothers who were military officers.