Career
Educated at Charterhouse School and the Royal Military Academy Sandhurst, Hartley was commissioned into the 68th Durham Light Infantry as a second lieutenant on 8 January 1901, He was promoted to lieutenant on 10 May 1905 (seniority 5 June 1903) and transferred to the Indian Army that year. He served in the Second Boer War and in World War I being mentioned in dispatches three times and awarded the Defence Science Organisation. He was promoted to captain on 8 January 1910, to major in June 1917 and to acting lieutenant-colonel in 1917. In 1921 he became a General Staff Officer in India and in 1925 he was made an Instructor at the Staff College at Quetta.
He then became Commanding Officer of the 5th King Edward"s Own Probyn"s Horse Regiment.
In 1931 he became Commander of the 4th (Secunderabad) Cavalry Brigade after which he was made Director of Military Operations and Intelligence at Army Headquarters in New Delhi. A brigadier by 1935, he was appointed a Companion of the Order of the Bath (Central Bank) in the 1936 New Year Honours and promoted to major-general on 9 January 1936.
He was appointed Commander of Waziristan District in the same year. By the start of World World War II he was Commander of Rawalpindi District.
On 6 June 1940, he was appointed General Officer Commanding-in-Chief Northern Command, India and promoted to lieutenant-general.
He was promoted to full general in the Indian Army on 27 January 1941 and knighted in that year"s Birthday Honours list as a Knight Commander of the Order of the Star of India (KCSI). In January 1942 he succeeded General Sir Archibald Wavell for a short time as Commander-in-Chief, India. Wavell was reappointed in March 1942 and Hartley was appointed Deputy Commander in Chief.
In Spring 1942 he was fighting the Japanese on the Eastern border of India.
He retired in 1944.