Educated at Reading School. Obtained direct entry into the Royal Military Academy Sandhurst. Commissioned Second Lieutenant Indian Army 19 January 1907. During WWI, Atkinson, a member of the 17th Indian Cavalry, served with the 15th Hussars and Royal Irish Lancers. Served in France and Belgium from August 1914. Promoted to Captain 19 January 1916. Mentioned in Despatches 28 December 1917.

Remained in the Indian Army in the immediate post-war years. Served in Afghanistan in 1919 on the North West Frontier and again from 1919 to 1921. He received another Mention in Despatches for his service there. Promoted to Major in 1922 and transferred to the 15th Indian Lancers. In 1933 he was promoted to Lieutenant Colonel and was commanding the 15th by 1934. Appointed MVO (4th class) King's Birthdays Honours 1934. Retired 9 October 1937.

Re-called WWII reverting to the rank of Major 1 July 1940. Major (A/Lieutenant Colonel) reverted to the rank of Lieutenant Colonel 5 June 1941. Appointed Acting Colonel 23 June 1941. Attached 1 Special Service Brigade sometime after its formation August 1943. 1944 posted Home Guard training. Member of the Commando Association.