I Corps (United Kingdom)


I Corps ("First Corps") was an army corps in existence as an active formation in the British Army for most of the 80 years from its creation in the First World War until the end of the Cold War, longer than any other corps. It had a short-lived precursor during the Waterloo Campaign.

I Corps
I Corps.svg
I Corps formation badge during the Second World War.[1]
ActiveWaterloo Campaign
First World War
Second World War
Cold War 1951–1994
Country United Kingdom
BranchFlag of the British Army.svg British Army
TypeField corps
EngagementsWaterloo Campaign

First World War[2]

Second World War

The Prince of Orange
Sir Douglas Haig
Sir Charles Monro
Sir Hubert Gough
Sir Arthur Holland
Sir John Dill
Sir Harold Alexander
John Crocker
Corps formation sign during the First World War.[3]I corps WW1.svg

Napoleonic precursorEdit

Assembling an army in Belgium to fight Napoleon's resurgent forces in the spring of 1815, the Duke of Wellington formed it into army corps, deliberately mixing units from the Anglo-Hanoverian, Dutch-Belgian and German contingents so that the weaker elements would be stiffened by more experienced or reliable troops. As he put it: 'It was necessary to organize these troops in brigades, divisions, and corps d’armee with those better disciplined and more accustomed to war'.[4] He placed I Corps under the command of the Prince of Orange and it was this corps that was first contacted by the advancing French at Quatre Bras on 16 June 1815. However, Wellington did not employ the corps as tactical entities, and continued his accustomed practice of issuing orders directly to divisional and lower commanders. When he drew up his army on the ridge at Waterloo, elements of the various corps were mixed up, and although he gave the Prince of Orange nominal command of the centre, that officer had different forces under him. Subsequent to the battle, the corps structure was re-established for the advance into France, I Corps being commanded by Maj-Gen Sir John Byng, the Prince of Orange having been wounded at Waterloo.[5]

Composition of I Corps in the Waterloo CampaignEdit

General Officer Commanding (GOC): General The Prince of Orange

Prior to the First World WarEdit

After Waterloo the army corps structure largely disappeared from the British Army, except for ad hoc formations assembled during annual manoeuvres (e.g. Army Manoeuvres of 1913). In 1876 a Mobilisation Scheme for eight army corps was published, with 'First Corps' based on Colchester. In 1880 First Corps' organization was:

  • 1st Division (Colchester)
  • 2nd Division (Chelmsford)
    • 1st Brigade (Chelmsford)
    • 2nd Brigade (Warley)
    • Divisional Troops
    • Artillery
      • I/4th Brigade RA (Newcastle), N/4th Brigade RA (Woolwich), M/4th Brigade RA (Newcastle)
  • 3rd Division (Gravesend)
  • Cavalry Brigade (Maldon)
  • Corps Artillery (Colchester)
    • E Battery C Brigade RHA (Woolwich), H Battery A Brigade RHA (Woolwich)
    • G/1st Brigade RA (Woolwich), B/5th Brigade RA (Sheffield)
  • Corps Engineers (Colchester)
    • A (Pontoons) Troop Royal Engineer Train (Aldershot)
    • C (Telegraph) Troop Royal Engineer Train (Aldershot)
    • 23rd Company Royal Engineers and Field Park (Chatham)

This scheme had been dropped by 1881.[6] The Stanhope Memorandum of 1891 (drawn up by Edward Stanhope when Secretary of State for War) laid down the policy that after providing for garrisons and India, the army should be able to mobilise three army corps for home defence, two of regular troops and one partly of militia, each of three divisions. Only after those commitments, it was hoped, might two army corps be organised for the unlikely eventuality of deployment abroad.[7]

When the Second Anglo-Boer War was imminent in September 1899, a field army, referred to as the Army Corps (sometimes I Army Corps) was mobilised and sent to Cape Town. It was, in fact, 'about the equivalent of the First Army Corps of the existing mobilization scheme',[8] and was placed under the command of Gen Sir Redvers Buller, General Officer Commanding-in-Chief of Aldershot Command. However, once in South Africa the corps never operated as such, and the three divisions (1st, 2nd and 3rd) were widely dispersed.

The 1901 Army Estimates introduced by St John Brodrick allowed for six army corps based on the six regional commands (Aldershot, Southern, Irish, Eastern, Northern and Scottish) of which only I Corps (Aldershot Command) and II Corps (Southern Command on Salisbury Plain) would be entirely formed of regular troops.[9] However, these arrangements remained theoretical, the title 'I Corps' being added to Aldershot Command. In early October 1902 a memorandum was issued showing the organization and allocation of the 1st Army Corps, to which Sir John French had recently been appointed in command:[10]

In 1907 the title changed to 'Aldershot Corps' but reverted to simply 'Aldershot Command' the following year.[11] Finally, the Haldane Reforms of 1907 established a six-division British Expeditionary Force for deployment overseas, but only Aldershot Command possessed two infantry divisions and a full complement of 'army troops' to form an army corps in the field.[12]

First World WarEdit

Pre-war planning for the British Expeditionary Force (BEF) did not envisage any intermediate headquarters between GHQ and the six infantry divisions, but it was assumed that if corps HQs became necessary, then the GOC Aldershot Command would automatically become GOC I Corps in the field.[13] On mobilisation in August 1914 the decision was made to conform to the two-division army corps organisation employed by the French armies alongside which the BEF was to operate.[14] Sir Douglas Haig, then commanding at Aldershot, therefore took I Corps HQ to France with 1st Division and 2nd Division under command, and it remained on the Western Front throughout the war. It had a peripheral part at the Battle of Mons, then saw hard fighting at the Battle of the Aisne and First Battle of Ypres in 1914, at the Battle of Aubers Ridge in the Spring of 1915 and alongside the Canadian Corps at the Battle of Hill 70, as well in many other large battles of the First World War.

Composition of I Corps in First World WarEdit

The composition of army corps changed frequently. Some representative orders of battle for I Corps are given here.

Order of Battle at Mons 23 August 1914[15]

General Officer Commanding: Lieut-Gen Sir Douglas Haig

By the time of the battles of Aubers Ridge and Festubert (May 1915), I Corps still had 1st and 2nd Divisions under command, but had been reinforced by 47th (1/2nd London) Division of the Territorial Force, and 1st Canadian Division.[17] Once the era of trench warfare had set in on the Western Front (1915–17), the BEF left its army corps in position for long periods, so that they became familiar with their sector, while rotating divisions as they required rest, training, or transfer to other sectors.[18]

From May 1916 to August 1917, I Corps Cavalry Regiment was provided by the 1st South Irish Horse.[19]

On 25 September 1918, for the final battles, I Corps was transferred from First Army to Sir William Birdwood's Fifth Army.[20]

Order of Battle during the final advance in Artois 2 October-11 November 1918[2][21]

General Officer Commanding: Lieut-Gen Sir Arthur Holland
BGGS: Brig-Gen G.V. Hordern
Deputy Adjutant & Quartermaster-General: Brig-Gen N.G. Anderson
Commander, Royal Artillery: Brig-Gen H.C. Sheppard
Commander, Heavy Artillery: Brig-Gen F.G. Maunsell
Commander, Engineers: Brig-Gen H.W. Gordon

Second World WarEdit

Battle of FranceEdit

General Sir John Dill, General Officer Commanding I Corps, inspecting soldiers digging trenches at Flines, France. Stood three away from is his Brigadier General Staff (BGS), Brigadier Arthur Percival.

During the Second World War, I Corps' first assignment was again to the British Expeditionary Force (BEF) where it was commanded by General Sir John Dill, and then Lieutenant General Michael Barker from April 1940. After the Germans broke through Allied lines in the Battle of France in May 1940, the BEF was forced to retreat to Dunkirk for evacuation to England. The Commander-in-Chief (C-in-C) of the BEF, General Lord Gort, ordered Barker to form the rearguard with I Corps to cover the evacuation, and surrender to the Germans as a last resort. However, the acting commander of II Corps, Major General Bernard Montgomery, advised Gort that Barker was in an unfit state to be left in final command, and recommended that Major General Harold Alexander of the 1st Division should be put in charge. Gort did as Montgomery advised, and in the event the bulk of I Corps was successfully evacuated. As Montgomery recalled: '"Alex" got everyone away in his own calm and confident manner'.[24]

Composition of I Corps in the Battle of FranceEdit

The order of battle was as follows:[25]
General Officer Commanding: Lieutenant General M.G.H. Barker

North-West EuropeEdit

After returning to England I Corps then remained in the United Kingdom, based at Hickleton Hall in South Yorkshire within Northern Command on anti-invasion duties, preparing defences to repel a German invasion of the United Kingdom.[33]

Lieutenant General John Crocker, pictured here in August 1944.

I Corps, now commanded by Lieutenant General John Crocker, then took part in the Normandy landings on 6 June 1944 where, along with XXX Corps, under Lieutenant General Gerard Bucknall (who had commanded I Corps between April and August 1943), it was a spearhead corps of Lieutenant General Miles Dempsey's British Second Army, itself part of the 21st Army Group. The corps was then involved in the Battle of Normandy in fierce attritional fighting for control of the Normandy beachhead. After fighting for two months in the Battle for Caen, I Corps was subordinated on 1 August 1944 to the Canadian First Army, commanded by Lieutenant General Harry Crerar, for the remainder of the Normandy campaign [34] and the subsequent operations in the Low Countries.[35] During Operation Pheasant, I Corps was unique in that it fielded multi national divisionsm - Polish 1st Armoured Division, the Canadian 4th Armoured Division the British 49th Polar Bears Division and the US 104th Timberwolf Division. After the Battle of the Scheldt I Corps Headquarters then took over administration of the 21st Army Group's logistics area around the port of Antwerp, Belgium until the end of the war.

Composition of I Corps in NW Europe CampaignEdit

General Officer Commanding: Lieutenant-General John Crocker


Assignments of corps to armies, and divisions to corps, changed frequently during the campaign:

As of 6 June 1944[46]

As of 7 July 1944

As of 1 August 1944 (now part of First Canadian Army)

British Army of the RhineEdit

After the defeat of Germany, the 21st Army Group became the British Army of the Rhine (BAOR), and 1 Corps, under the command of Lieutenant-General Ivor Thomas, was transformed into a corps district, with an administrative, rather than combat, role. It was disbanded in 1947.[47]

However, in October 1951 the corps was reactivated to become the principal combat element of the BAOR, with its HQ based in Bielefeld. In March 1952, following the reactivation of 6th Armoured Division, its component formations were:

Included as part of this was Canada's contribution to the NATO land forces in Germany. A Canadian mechanised brigade remained part of BAOR until 1970. The size of this force, 6,700, was such that it was referred to within British circles as a "light division".

4th Division was reformed from 11th Armoured Division on 1 April 1956.[48]

In a following 1958-60 reorganisation the Corps was formed into three mixed armour/infantry divisions including five brigade groups, which were in 1965 brought together into three centralised divisions (1st, 2nd, and 4th). In 1958, the "infantry" designation was dropped from the 2nd Infantry Division's title as part of this reorganisation.[49] During the 1970s, 4th Division consisted of two "square" brigades.[50]

With the end of National Service, manpower across the whole of BAOR dropped from around 77,000 to 55,000.

In the late 1970s the Corps was reorganised as four small five-battle-group armoured divisions plus a roughly brigade sized infantry 'Field Force'. It then comprised:

Following the 1981-3 reorganisation, the Corps consisted of 1st and 4th Armoured Divisions, which would have manned the front line against the anticipated attack by the Soviet 3rd Shock Army, plus in an in-depth, reserve role the 3rd Armoured Division and finally the 2nd Infantry Division which was tasked with rear-area security.[52]


With the end of the Cold War, in 1992 1 (BR) Corps was disbanded, and its HQ closed. Some of the staff serving in HQ 1(BR) Corps were reassigned to the new HQ UK Support Command (Germany) which was formed from the rump of HQ BAOR. The remainder of the staff formed the British component (50% of the total staff in the HQ) in the Headquarters Allied Command Europe Rapid Reaction Corps (HQ ARRC), a newly instated multi-national NATO Rapid Reaction Corps HQ. The Corps Commander reported to the Supreme Allied Commander Europe SACEUR, but had no troops under command except when assigned to ARRC by NATO member nations, for operations or for exercises. HQ ARRC moved to Rheindahlen in 1994.

General Officers CommandingEdit

Commanders have included:[53]

From 1901 to 1905 the commander of the troops at Aldershot was also commander 1st Army Corps

Note: I Corps was disbanded at the end of the First World War and reformed at the start of the Second World War

Note: I Corps was disbanded in June 1947 and reformed in late 1951[47]


  1. ^ Cole p. 126
  2. ^ a b The long, long trail
  3. ^ JPS card no. 92
  4. ^ Hofschroer, Ligny and Quatre Bras, p.109.
  5. ^ Hofschroer, The German Victory, p.201.
  6. ^ Army List 1876–1881.
  7. ^ Dunlop ch 2.
  8. ^ Dunlop p 72.
  9. ^ Dunlop pp 130-40.
  10. ^ "Naval & Military intelligence - The 1st Army Corps". The Times. No. 36892. London. 7 October 1902. p. 8.
  11. ^ Army List
  12. ^ Dunlop p 262.
  13. ^ Neillands, p. 169.
  14. ^ Official History 1914, Volume I, p. 7.
  15. ^ Official History 1914, Volume I, Appendix 1.
  16. ^ Sir John French, Operation Order No 5, Official History 1914, Volume 1, Appendix 10.
  17. ^ Official History 1915, Volume I, Appendix 2.
  18. ^ Sanders Marble, 'Offensive versus Subsidiary Attacks, 1916–1918: The British Expeditionary Force Balancing its Options', Journal of the Society for Army Historical Research, Volume 87, No 351 (Autumn 2009).
  19. ^ James, p. 15.
  20. ^ Official History 1918 Volume 5, p 125.
  21. ^ Official History 1918 Volume 5, p 125 and Appendix I
  22. ^ Watson & Rinaldi, p. 22.
  23. ^ Lord & Watson, p. 234.
  24. ^ Montgomery p. 64
  25. ^ Ellis, Major L.F. "The War in France and Flanders 1939-40, Appendix I". UK Military Series.
  26. ^ "1 Corps".
  27. ^ "27 Field Regiment RA".
  28. ^ "140 (5th London) Field Regiment RA (TA)". Retrieved 20 August 2010.
  29. ^ "3 Medium Regiment RA".
  30. ^ "5 Medium Regiment RA".
  31. ^ "52 (East Lancashire) Light AA Regiment RA (TA)".
  32. ^ "1 Survey Regiment RA".
  33. ^ Newbold, p. 202
  34. ^ Hart, p.19
  35. ^ Williams, p. 466. participating in Operation Astonia, the capture of Le Havre, and the operations to clear the Channel Coast, later helping to garrison "The Island" area between Arnhem and Nijmegen in the aftermath of the failed airborne invasion of the Netherlands, Operation Market Garden.
  36. ^ Forty, p 346.
  37. ^ "102 Light AA Regiment RA (TA)". Archived from the original on 2 March 2012. Retrieved 11 January 2010.
  38. ^ "9 Survey Regiment RA".
  39. ^ "4th Army Group RA".
  40. ^ "150 (S Notts Hussars Yeo) Field Regiment RA (TA)". Archived from the original on 31 January 2013. Retrieved 11 January 2010.
  41. ^ "53 (London) Medium Regiment RA (TA)".
  42. ^ "65 Medium Regiment RA (TA)". Archived from the original on 10 June 2010. Retrieved 11 January 2010.
  43. ^ "68 Medium Regiment RA (TA)".
  44. ^ "79 (Scottish Horse) Medium Regiment RA (TA)".
  45. ^ "51 (Lowland) Heavy Regiment RA (TA)".
  46. ^ Ellis, p.181
  47. ^ a b The British Army in Germany: An Organizational History 1947-2004 By Graham Watson, Richard A. Rinaldi, Page 11 Tiger Lily, 2005, ISBN 978-0-9720296-9-8
  48. ^ "4th Division". Regiments.org. Archived from the original on 29 December 2006. Retrieved 20 May 2020.
  49. ^ Lord & Watson 2003, p. 28.
  50. ^ Watson, Graham (2005). The British Army in Germany: An Organisational History 1947–2004. Tiger Lily. p. 95. ISBN 9780972029698.
  51. ^ "History of BAOR". BAOR Locations. Retrieved 27 October 2015.
  52. ^ Isby & Kamps, pp.256-258
  53. ^ Army Commands Archived 5 July 2015 at the Wayback Machine
  54. ^ "No. 27360". The London Gazette. 1 October 1901. p. 6400.
  55. ^ "No. 27370". The London Gazette. 1 November 1901. p. 7048.
  56. ^ "No. 27477". The London Gazette. 26 September 1902. p. 6151.


  • Cole, Howard (1973). Formation Badges of World War 2. Britain, Commonwealth and Empire. London: Arms and Armour Press.
  • Dunlop, Colonel John K., The Development of the British Army 1899–1914, London, Methuen (1938).
  • Ellis, John, The World War II Databook. BCA Publishing, 2003. CN 1185599.
  • Forty, George, British Army Handbook 1939-1945, Sutton Publishing (1998).
  • Hart, Stephen, Road To Falaise, Sutton Publishing (2004).
  • Hofschroer, Peter, 1815: The Waterloo Campaign: Wellington, his German Allies and the Battles of Ligny and Quatre Bras, London: Greenhill Books (1998) (ISBN 1-85367-304-8).
  • Hofschroer, Peter, 1815: The Waterloo Campaign: The German Victory, London: Greenhill Books (1999) (ISBN 1-85367-368-4).
  • Isby, David, & Kamps, Charles Jr, Armies of NATO's Central Front, Jane's Publishing Company (1985).
  • Brig E.A. James, British Regiments 1914–18, London: Samson Books, 1978, ISBN 0-906304-03-2/Uckfield: Naval & Military Press, 2001, ISBN 978-1-84342-197-9.
  • JPS Cigarette card series, Army, Corps and Divisional Signs 1914–1918, John Player and sons, 1920s.
  • Lord, Cliff; Watson, Graham (2003). The Royal Corps of Signals : unit histories of the Corps (1920-2001) and its antecedents. Solihull, West Midlands, England: Helion & Company. ISBN 1-874622-92-2. OCLC 184820114. ProQuest 5774170.
  • Montgomery, Viscount, The Memoirs of Field-Marshal Montgomery, London: Collins (1958).
  • Neillands,Robin The Great War Generals on the Western Front 1914-18, London: Robinson Publishing (1999).
  • Newbold, David John. "British planning and preparations to resist invasion on land, September 1939 - September 1940". King's College, University of London.
  • Official History 1914: Edmonds, Brigadier-General Sir James E., Military Operations France and Belgium, 1914, Volume I: Mons, the Retreat to the Seine, the Marne and the Aisne, August–October 1914 3rd revised edn 1933 (reprint Imperial War Museum, 1992) (ISBN 1870423569).
  • Official History 1915: Edmonds, Brigadier-General Sir James E., and Wynne, Capt G.C., Military Operations France and Belgium, 1915 Volume II: Battle of Aubers Ridge, Festubert, and Loos, London: Macmillan, 1928.
  • Official History 1918: Edmonds, Brigadier-General Sir James E., Military Operations France and Belgium, 1918 Volume V: 26 September–11 November: The Advance to Victory 1947 (reprint Imperial War Museum, 1992) (ISBN 1-870423-06-2).
  • Official History 1939-40: Ellis, Major L.F., History of the Second World War, United Kingdom Military Series: The War in France and Flanders 1939-1940, London: HMSO, 1954.
  • The National Archives, WO 171/258-260, I Corps HQ War Diaries, January - December 1944.
  • Graham E. Watson & Richard A. Rinaldi, The Corps of Royal Engineers: Organization and Units 1889–2018, Tiger Lily Books, 2018, ISBN 978-171790180-4.
  • Williams, Mary H., (compiler), "U. S. Army in World War II, Chronology 1941-1945", Washington D.C.: Government Printing Office (1958).

External sourcesEdit

  • The Long Long Trail
  • Official History 1939-40
  • Royal Artillery 1939-45
  • British Army Locations from 1945
  • Regiments.org
  • Late 70s-82 order of battle
  • 1989 order of battle