26 Sept 1914 Temporary Commission Lieutenant RAMC.
26 Sept 1915 Captain RAMC.
1915–1919 Served in France.
20 Mar 1920 Demobilised.
18 June 1920 Permanent Regular Army Commission Captain RAMC.
1921–1925 Served in Egypt.
25 Dec 1926 Major RAMC.
1928 Specialist in medicine.
1929–1934 Served in Egypt.
1935–1937 Medical Specialist Cambridge Military Hospital Aldershot.
30 Oct 1937 Retired but rejoined on 2 Sept 1939.
Sep 1939–May1940 Medical Specialist 3 Casualty Clearing Station BEF, France.
13 Feb 1941 Acting Lieutenant Colonel RAMC.
1941 Officer-in-Charge Medical Division 4th General Hospital.
16 Sept 1941 Reported to No 11 Depot and Training Establishment RAMC Leeds on the incorporation of No 39 General Hospital.
Officer-in-charge Medical Division 39 GH St Andrews.
Malta 1942 Officer-in-Charge Medical Division 39 General Hospital St Andrews.
Malta 19 May 1942 Reported on the suitability of using the site at Mellieha Infantry Camp as a tented 200-300 bed hospital for 39 GH, which had been destroyed by enemy bombing at St Andrews on 25 April. In his opinion the site was most suitable for that type of psychological case for whom the co-ordinating physician had asked for an improved convalescent camp, and for the disposal of invalids awaiting passage to England, for whom surgery was no longer required. Col Coles was of the opinion that it would be quicker to rebuild on the original St Paul's Hutments and St Andrews sites.
Malta 1943 Officer-in-Charge Medical Division 39th General Hospital.
Malta 24 July–19 Aug 1943 Acting Colonel L/RAMC. Took temporary command of 39th GH following the posting of Colonel to 4 GH on 22 July, and until the arrival of Colonel W I Fitzgerald Powell on 19 August.
3–8 Sep 1943 On local leave.
Malta 22 Apr 1944 Left for England.
1944–1945 Officer-in-Charge 75th General Hospital North West Europe.
1 Sep 1960 Died at Coombe Cottage Fittleworth Sussex aged 69 years.