4 Dec 1899 Appointed Lieutenant RAMC. Educated at the University of Durham.
Dec 1899 Detailed to No 7 Bearer Company (14th Brigade), together with Maj Faunce Charles Edmund and Capt C E G Stalkarlt.
1900 – 1902 Served in South Africa as medical officer to the 2nd Battalion Lincolnshire Regiment. He was present at the battle of Paardeberg and the occupation of Johannesburg and Pretoria. He received the King's Medal with two clasps and the Queen's Medal with three clasps.
4 Dec 1902 Promoted Captain RAMC. Returned to England from South Africa.
1903 – 1905 Served in India. Returned to England in 1905.
Malta 7 Sep 1910 Arrived from Shorncliffe England.
Malta 7 Aug 1911 Home leave.
4 Sep 1911 Promoted Major RAMC. Company Officer.
Malta 8 Sep 1911 Returned to Malta.
Malta 15 Sep 1911 Left for Tientsin North China. Replaced in Malta by Maj Evans Charles Robert from England.
16 Sep 1911 – 1914 Served in North China.
The Republic of China was proclaimed in 1911 following the overthrow of the Manchu or Tai-Tsing Dynasty by a rebellion which had its origin at Wu-Chang on the Yang-Tse river.
Sept 1914 – 1915 Senior Medical Officer on Tsingtau Expeditionary Force as part of an Anglo–Japanese Force to expel Germany from its protectorate of Kiao-chau, in China, which it had seized in Mar 1898.
Tsingtau was a modern fortress town built by Germany at the mouth of the harbour. On 15 Aug 1914, Japan presented Germany an ultimatum demanding the immediate withdrawal of its warships from Chinese waters, and the handing over to Japan of the complete territory of Kiao–chau for eventual restoration to China.
The British Contingent landed in Shantung on 21st Sept 1914 and supported the Japanese in forcing the surrender of Tsingtau on 7 Nov 1914.
13 Nov 1914 Mentioned in despatches of the Tsingtau Expeditionary Force Commander Brigadier–General Nathaniel Barnardiston.
1915 – 1919 Served in France.
14 Jan 1916 Made a Companion of the Distinguished Service Order (DSO) with effect from 1 January 1916.
26 Dec 1917 Promoted Lieutenant Colonel RAMC.
1917 Commanding Officer 19 Casualty Clearing Station.
1917 – 1918 Commanding Officer 48 Casualty Clearing Station.
3 June 1918 Appointed Companion Order of St Michael and St George (CMG).
1918–1919 Assistant Director of Medical Services HQ 19 Div.
3 June 1919 Promoted Brevet Colonel L/RAMC.
1919 – 1922 ADMS HQ Aldershot Command.
1920 General Hartigan married Miss Marion Smith.
1922 – 1924 Senior Medical Officer Jamaica.
1925 – 1927 Commanding Officer Royal Herbert Hospital Woolwich.
3 Jan 1927 Appointed King's Honorary Physician (KHP).
22 Oct 1927 Colonel L/RAMC.
1927 – 1930 Assistant Director of Medical Services HQ Home Counties Area (West).
20 Mar 1930 Major-General.
3 June 1933 Appointed Companion Order of the Bath (CB military division).
1930 – 1934 Deputy Director of Medical Services HQ Aldershot Command.
1 Mar 1934 Lieutenant General.
3 June 1935 Appointed Knight Commander of The Most Honourable Order of the Bath (KCB).
1934 – 1938 Director General Army Medical Services War Office.
1 Mar 1938 Retired.
1941 Colonel Commandant RAMC.