I Corps (United Kingdom)

I 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 World War I until the end of the Cold War, longer than any other corps. It had a short-lived precursor during the Waterloo Campaign.

Napoleonic precursor
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’. 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.

Composition of I Corps in the Waterloo Campaign
GOC: General HRH The Prince of Orange


 * 1st (British) Division (British Guards)
 * 3rd (British) Division (Anglo-Hanoverian)
 * 2nd (Netherlands) Division (Dutch-Belgian)
 * 3rd (Netherlands) Division (Dutch-Belgian)

Prior to World War I
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)
 * 1st Brigade (Colchester)
 * 1st Bn. 2nd Foot (Colchester), 1st Bn. 10th Foot (Colchester)
 * 2nd Brigade (Colchester)
 * 1st Bn. 9th Foot (Kinsale), 28th Foot (Fermoy)
 * Divisional Troops
 * 2nd Bn. 12th Foot (Portsmouth), Buckinghamshire Yeomanry (Buckingham), 1st Company Royal Engineers (Shorncliffe)
 * Artillery
 * F/1st Brigade Royal Artillery (Ipswich), D/1st Brigade RA (Woolwich)
 * 2nd Division (Chelmsford)
 * 1st Brigade (Chelmsford)
 * 1st Bn. 15th Foot (Tipperary), 47th Foot (The Curragh)
 * 2nd Brigade (Warley)
 * 1st Bn. 3rd Foot (Shorncliffe), 49th Foot (Dover), 55th Foot (Shorncliffe)
 * Divisional Troops
 * 1st Bn. 23rd Foot (Woolwich), Hertfordshire Yeomanry (St Albans), 20th Company Royal Engineers (Chatham)
 * Artillery
 * I/4th Brigade RA (Newcastle), N/4th Brigade RA (Woolwich), M/4th Brigade RA (Newcastle)
 * 3rd Division (Gravesend)
 * 1st Brigade (Gravesend)
 * 77th Foot (Dublin), 104th Foot (Belfast), 105th Foot (Newry)
 * 2nd Brigade (Chatham)
 * 2nd Bn. 5th Foot (Chatham), 31st Foot (Chatham), 86th Foot (Chatham)
 * Divisional Troops
 * 87th Foot (Limerick), West Kent Yeomanry (Maidstone), 22nd Company Royal Engineers (Woolwich)
 * Artillery
 * O/4th Brigade RA (Weedon), A/5th Brigade RA (Weedon)
 * Cavalry Brigade (Maldon)
 * 3rd Hussars (Colchester), 4th Hussars (Shorncliffe), Suffolk Yeomanry (Bury St Edmunds), F Battery C Brigade Royal Horse Artillery (Canterbury)
 * 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. 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. When war with the Boer Republics was imminent in September 1899, a Field Force, referred to as the Army Corps (sometimes 1st 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', and was placed under the command of Gen Sir Redvers Buller, GOCinC 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. However, these arrangements remained theoretical, the title 'I Corps' being added to Aldershot Command. In 1907 the title changed to 'Aldershot Corps' but reverted to simply 'Aldershot Command' the following year. 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.

World War I
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. 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. 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 World War I.

Composition of I Corps in World War I
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

GOC: Lieut-Gen Sir Douglas Haig
 * Brigadier-General, General Staff (BGGS): J.E. Gough VC
 * Brigadier-General, Royal Artillery: H.S. Horne
 * Colonel, Royal Engineers: Brig-Gen S.R. Rice


 * 1st Division
 * 2nd Division


 * Army Troops attached (20 August 1914)
 * 1st Army HQ Signal Company, Royal Engineers
 * D (Air Line) Section
 * G, K & L (Cable) Sections
 * No 2 Section, 1st Printing Company, Royal Engineers
 * No 1 Bridging Train, Royal Engineers
 * B Squadron, North Irish Horse
 * Company, 1st Bn Cameron Highlanders
 * B & C Sections, No 19 Field Ambulance, RAMC

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. 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.

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

'''Order of Battle during the final advance in Artois 2 October-11 November 1918

GOC: 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
 * 15th (Scottish) Division
 * 16th (Irish) Division
 * 55th (West Lancashire) Division (transferred to III Corps on 8 October)
 * 58th (2/1st London) Division (transferred from VIII Corps/First Army on 14 October).

Battle of France
During World War II, I Corps' first assignment was again to the British Expeditionary Force where it was commanded by General Dill, and then Lieut-Gen Barker from April 1940. After the Germans broke through Allied lines in May 1940, the BEF was forced to retreat to Dunkirk for evacuation. The GOCinC, 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, Maj-Gen Bernard Montgomery, advised Gort that Barker was in an unfit state to be left in final command, and recommended that Maj-Gen Harold Alexander of 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'.

===Composition of I Corps in the Battle of France ===

GOC: Lt-Gen M.G.H. Barker
 * 1st Division
 * 2nd Division
 * 48th (South Midland) Division
 * Royal Artillery
 * 27th Army Field Regt (21/24 & 37/47 Batteries)
 * 140th (5th London) Army Field Regt (366 (10th London) & 367 (11th London) Batteries)
 * 3rd Medium Regt (2/11 & 6/10 Batteries)
 * 5th Medium Regt (15/17 & 20/21 Batteries)
 * 52nd (East Lancashire) Light Anti-Aircraft Regt (154, 155 & 156 Batteries)
 * 2nd Light Anti-Aircraft Battery
 * 1st Survey Regiment
 * Royal Engineers
 * 102nd, 107th, 221st Army Field Companies
 * 105th Corps Field Park Company
 * 13th Corps Field Survey Company
 * Infantry—Machine Gun
 * 2nd and 4th Battalions The Cheshire Regiment
 * 2nd Battalion The Manchester Regiment

North-West Europe
I Corps then remained in the United Kingdom until the landings in Normandy for Operation Overlord, where, along with XXX Corps, it was a spearhead corps of Second Army of 21st Army Group. After fighting for two months around Caen, the Corps was subordinated on 1 August 1944 to First Canadian Army for the remainder of the Normandy campaign and the subsequent operations in the Low Countries and Germany until 1 April 1945. I Corps Headquarters then took over administration of 21st Army Group's logistics area around the port of Antwerp, Belgium until the end of the war. During the North-West Europe campaign it was under the command of Lieutenant General John Crocker.

Composition of I Corps in NW Europe Campaign
GOC: Lt-Gen John Crocker Attached:
 * Corps troops:
 * The Inns of Court Regiment, Royal Armoured Corps (armoured cars)
 * 62nd Anti-Tank Regiment, RA (left November 1944 for Eighth Army)
 * 102nd Light Anti-Aircraft Regiment, RA
 * 9th Survey Regiment, RA
 * I Corps Troops, Royal Engineers
 * I Corps Signals
 * 4th Army Group, Royal Artillery
 * 150th (South Nottinghamshire Hussars Yeomanry) Field Regiment, RA (suspended animation January 1945)
 * 53rd (London) Medium Regiment, RA (209 & 210 (London) Batteries)
 * 65th Medium Regiment, RA (222 (Fraserborough) & 223 (Banffshire) Batteries)
 * 68th Medium Regiment, RA (212 & 233 Batteries)
 * 79th (Scottish Horse) Medium Regiment, RA
 * 51st (Lowland) Heavy Regiment, RA

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

As of 6 June 1944
 * 3rd Infantry Division
 * Canadian 3rd Infantry Division
 * 6th Airborne Division

As of 7 July 1944
 * 3rd Infantry Division
 * Canadian 3rd Infantry Division
 * 51st (Highland) Infantry Division
 * 59th (Staffordshire) Infantry Division
 * 6th Airborne Division

As of 1 August 1944 (now part of First Canadian Army)
 * 51st (Highland) Infantry Division
 * 6th Airborne Division (returns to UK 3 September 1944)
 * 49th (West Riding) Infantry Division

British Army of the Rhine
After the defeat of Germany, 21st Army Group became the British Army of the Rhine (BAOR), and I Corps was transformed into a corps district, with an administrative, rather than combat, role. It was disbanded in 1947.

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:
 * 2nd Infantry Division
 * 6th Armoured Division
 * 7th Armoured Division
 * 11th Armoured Division

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".

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. 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:
 * 1st Armoured Division
 * 2nd Armoured Division
 * 3rd Armoured Division
 * 4th Armoured Division
 * 5th Field Force

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.


 * 1st Armoured Division
 * 7th Armoured Brigade
 * 12th Armoured Brigade
 * 22nd Armoured Brigade
 * 3rd Armoured Division
 * 4th Armoured Brigade
 * 6th Armoured Brigade
 * 33rd Armoured Brigade
 * 4th Armoured Division
 * 11th Armoured Brigade
 * 20th Armoured Brigade
 * 19th Infantry Brigade (in UK)
 * 2nd Infantry Division (in UK)
 * 15th Infantry Brigade (TA)
 * 24th Airmobile Brigade
 * 49th Infantry Brigade (TA)
 * Artillery Division (HQ Ripon Barracks, Bielefeld)



With the end of the Cold War, I (BR) Corps was redesignated in 1992 as a NATO Rapid Reaction Corps under SACEUR and renamed as Headquarters Allied Command Europe Rapid Reaction Corps. HQ ARRC moved to Rheindahlen in 1994.

General Officers Commanding
Commanders have included: Note: I Corps was disbanded at the end of World War I and reformed at the start of World War II Note: I Corps was disbanded in June 1947 and reformed in late 1951
 * 1815 General The Prince of Orange
 * 1 October 1901- ? General Sir Redvers Buller
 * 1914 Lieutenant-General Sir Douglas Haig
 * 1914–1915 Lieutenant-General Sir Charles Monro
 * 1915–1916 Lieutenant-General Sir Hubert Gough
 * 1917–1918 Lieutenant-General Sir Arthur Holland
 * 1939–1940 General Sir John Dill
 * 1940 Lieutenant-General Michael Barker
 * 1940 Lieutenant-General Harold Alexander
 * 1940–1941 Lieutenant-General Laurence Carr
 * 1941–1942 Lieutenant-General Henry Willcox
 * 1942–1943 Lieutenant-General Frederick Morgan
 * Apr-Aug 1943 Lieutenant-General Gerard Bucknall
 * 1943–1945 Lieutenant-General John Crocker
 * 1945 Lieutenant-General Sidney Kirkman
 * 1945–1947 Lieutenant-General Ivor Thomas
 * 1951–1953 Lieutenant-General Sir Dudley Ward
 * 1953–1954 Lieutenant-General Sir James Cassels
 * 1954–1956 Lieutenant-General Sir Hugh Stockwell
 * 1956–1958 Lieutenant-General Sir Harold Pyman
 * 1958–1960 Lieutenant-General Sir Michael West
 * 1960–1962 Lieutenant-General Sir Charles Jones
 * 1962–1963 Lieutenant-General Sir Kenneth Darling
 * 1963–1966 Lieutenant-General Sir Richard Goodwin
 * 1966–1968 Lieutenant-General Sir John Mogg
 * 1968–1970 Lieutenant-General Sir Mervyn Butler
 * 1970–1972 Lieutenant-General Sir John Sharp
 * 1972–1974 Lieutenant-General Sir Roland Gibbs
 * 1974–1976 Lieutenant-General Sir Jack Harman
 * 1976–1978 Lieutenant-General Sir Richard Worsley
 * 1978–1980 Lieutenant-General Sir Peter Leng
 * 1980–1983 Lieutenant-General Sir Nigel Bagnall
 * 1983–1985 Lieutenant-General Sir Martin Farndale
 * 1985–1987 Lieutenant-General Sir Brian Kenny
 * 1987–1989 Lieutenant-General Sir Peter Inge
 * 1989–1991 Lieutenant-General Sir Charles Guthrie
 * 1991–1992 Lieutenant-General Sir Jeremy Mackenzie

External sources

 * 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