Following the British evacuation of Gallipoli, the corps was moved to France in 1916, where it was commanded by Alexander Hamilton-Gordon until he was relieved in 1918. In September 1918 the following divisions joined the Corps:
6th Infantry Division
After severe losses during the Battle of the Lys in April 1918 the corps was moved south to a quiet sector to reform. This sector was the unlucky target of the next German offensive, the Third Battle of the Aisne in May–June 1918, causing further losses to IX Corps. GeneralDuchêne, commander of the French Sixth Army, had deployed IX corps too far forward, on the Chemin des Dames ridge which had been gained at such cost in the Second Battle of the Aisne the previous year. . At the time of the Armistice the IX Corps was part of the Fourth Army.
World War II
Disbanded in 1919 after the First World War ended, IX Corps was reformed during the Second World War in the United Kingdom in April 1941, under the command of Lieutenant General Ridley P. Pakenham-Walsh. The 59th Infantry Division and the Durham and North Riding County Division transferred to IX Corps from X Corps on 9 April 1941, which suggests this is the date the IX Corps became effective. The Northumberland County Division joined IX Corps the following day. The 15th Infantry Division transferred to join the corps, now commanded by Lieutenant General Edwin L. Morris, on 21 November 1941. On 30 November, both of the county divisions were disbanded, and on the following day, 1 December 1941, the corps was redesignated as IX Corps District. The 15th Division left the IX Corps District on 28 September 1942, to transfer to Northumbrian District, suggesting the corps temporarily ceased to be operational on this date. The IX Corps, now commanded by Lieutenant General John T. Crocker, was deployed to fight in North Africa under the command of Lieutenant General Kenneth A. N. Anderson's British First Army. The IX Corps headquarters, with Brigadier Gordon H. A. MacMillan as its chief of staff, landed in and opened as the reserve for the Allied18th Army Group on 24 March 1943. The 6th Armoured Division transferred to the corps from Lieutenant General Charles W. Allfrey's V Corps on 12 March 1943. The corps also took command of the U.S. 34th Infantry Division and the 128th Infantry Brigade Group, part of the 46th Infantry Division, and commenced an attack on Pinchon-Fondouk on the southern flank of the First Army. For the final offensive in North Africa several veteran formations from General Sir Bernard Montgomery's British Eighth Army arrived to reinforce the IX Corps, which was to play a leading role in the forthcoming offensive to end the war in North Africa. The British 7th Armoured Division, from the British Eighth Army, joined IX Corps on 30 April. The 4th Indian Infantry Division, also from the Eighth Army, joined on 30 April, followed by the 201st Guards Brigade, with the British 4th Infantry Division joining on 3 May. This gave IX Corps, now commanded by Lieutenant General Brian G. Horrocks, two armoured divisions and two infantry divisions. The final assault commenced on 5 May with the two infantry divisions forcing the Medjez-el-Bab gap, through which the two armoured divisions passed through to bring about the eventual surrender of the Axis forces on 13 May 1943. With the surrender of almost 250,000 Axis soldiers in North Africa, the IX Corps was run down. The 7th Armoured Division transferred to V Corps on 18 May 1943, the British 4th Infantry Division following it four days later, and the 6th Armoured Division on 26 May. IX Corps, with no commander after Horrocks returned to X Corps and as Crocker was still injured, was disbanded on 31 May 1943.
