I Corps (United Kingdom)

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

Prior to the First World War

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:

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.

First World War

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 the First World War.

Composition of I Corps in First World War

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

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

Battle of France

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'.

Composition of I Corps in the Battle of France

GOC: Lieutenant General M.G.H. Barker

North-West Europe

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.

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 and the subsequent operations in the Low Countries and Germany until 1 April 1945, 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 Campaign

GOC: Lieutenant-General John Crocker

Attached:

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

As of 6 June 1944

As of 7 July 1944

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

British Army of the Rhine

After the defeat of Germany, the 21st Army Group became the British Army of the Rhine (BAOR), and I Corps, under the command of Lieutenant-General Gwilym Ivor Thomas, 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:

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:

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.

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 Commanding

Commanders have included:

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