The 1st Army Corps () is a French army corps. It was first formed before World War I. During World War II it fought in the Battle for France in 1940, on the Mediterranean islands of Corsica and Elba in 1943–1944 and in the campaigns to liberate France in 1944 and invade Germany in 1945. The 1st Army Corps (1er Corps d'Armée) was recreated in 2026.

World War I The Corps saw service throughout the entirety of World War I. During the Battles of St. Quentin and Guise, the 1st Corps forced Karl von Bülow's 2nd Army into retreat in what historian Stuart Robson called "the last old-style Napoleonic infantry charge in history." This forced Alexander von Kluck to divert the 1st Army as a reinforcement, preventing the Imperial German Army from encircling Paris and overrunning France under the Schlieffen Plan.

The Corps participated in the Battle of Passchendaele as part of the First Army. At the time, the Corps comprised the 1st Division, 2nd Division, 51st Division and 162nd Division.J. E. Edmonds, Military Operations: France and Belgium, 1917 - Vol II, Pg 109 Its troops came from the 1st military region of the Metropolitan Army, which covered the départements of Nord & Pas-de-Calais.

Commanders in WW I 20 November 1913 : général Franchet d'Espérey 3 September 1914 : Général Deligny 25 February 1915 : général Guillaumat 17 December 1916 : Général de Riols de Fonclare 25 January 1917 : Général Muteau 19 April 1917 : Général Lacapelle 11 February 1919 : Général Nollet

World War II 1940 Campaign

1st Army Corps was constituted on August 27, 1939, in Lille under the command of Major General SciardThéodore Marcel Sciard, 1881–1967, commander of the Bas-Rhin Fortified Region, 43e DI, 3e DINA, and 1st Military Region prior to commanding the 1st Army Corps. After the 1940 campaign, commanded the 17th Military Region in 1940–1941 and then retired. Recalled in 1944 and retired again in 1945. as part of the French mobilization for war. Initially assigned as part of the First Army, the corps was transferred to the Seventh Army and moved to coastal regions near Calais and Dunkerque by mid-November 1939. On May 10, 1940, the Corps commanded the 25th Motorised Infantry Division (25e DIM) in addition to its organic units.

With the German invasion violating the neutrality of Belgium and the Netherlands on May 10, 1940, the 1st Army Corps moved into Belgium with the goal of gaining contact with the Dutch Army. This was achieved on May 12 near Breda, but the general failure of the Allies to hold the German advance mandated early retreats so that the 1st Army Corps would not be cut off. Breda fell to the Germans on May 13 and the corps conducted a fighting withdrawal through Dorp and Wuustwezel to the fortified zone of Antwerp, Belgium. From May 15 to 17, the corps defended the Scheldt Estuary with the 60th Infantry division and 21st Infantry Division (60e DI and 21e DI), but was ordered to retreat into France on May 18.Grandes Unités Françaises, Vol. I, p. 69

The period from May 19 to 26 saw the corps falling back to the line of the river Somme, where the French Army intended to make a stand. Because of German advances, the 1st Army Corps had to deploy its divisional reconnaissance units to cover positions on the river that the slower-moving infantry divisions (4th Colonial Infantry Division - 4e DIC, 7th North African Infantry Division - 7e DINA, and the 19e DI) could occupy. The corps reached positions near Le Hamel, Aubigny and along the road between Amiens and Saint-Quentin. During May 24 to 25, troops of the corps seized and lost Aubigny twice.Grandes Unités Françaises, Vol. I, pp. 69–71 The Germans had held onto a large bridgehead at Peronne. The Germans broke out of this bridgehead on June 5, 1940, and continued their advance into the heart of France. A counter-attack by armored elements of the corps on June 6 was halted by the Germans.

From June 9, the corps was involved in withdrawals that were meant to form lines of defense along the rivers Avre, Oise, Nonette, Seine, and Loire. The crossing of the Oise River was made under German air attack, some bridges were destroyed by the Luftwaffe, and portions of the corps' infantry had to surrender north of the Oise.

After the Germans crossed the Loire on June 18, the 19e DI of the corps was largely destroyed near La Ferté. This was followed by capture of the bulk of the infantry of the 29th (29e DI) and 47th Infantry Divisions (47e DI) on June 19 near Lamotte-Beuvron.Grandes Unités Françaises, Vol. I, p. 77 The final week of the campaign was a constant retreat for the remnants of the corps, with elements crossing the river Dordogne near Bergerac on June 24, 1940. The following day, an armistice was declared and the corps assembled in the region of Miallet and Thiviers.

On July 1, Brigadier General TrancartJacques Marie Joseph Edmond Ignace Trancart, 1881–1952, commander of 1st Army Corps Artillery prior to assuming corps command. assumed command of the corps. The 1st Army Corps was demobilized on July 10, 1940.

Corsica 1943

The 1st Army Corps was reconstituted on August 16, 1943, in Ain-Taya, French Algeria. Now commanded by Lieutenant General MartinHenry Jules Jean Martin, 1888–1984, commander of 87e DIA, Division Marrakech, and 1er DMM before commanding 1st Army Corps. Commander of XIX Corps in Algeria from 1944-1946, retired 1946. the primary combat units of the corps were provided American equipment and weapons as part of the rearmament of the French Army of Africa.

During the Allied invasion of Italy the 1st Army Corps, comprising Headquarters, 4th Moroccan Mountain Division (4e DMM), the 1st Regiment of Moroccan Tirailleurs (1er RTM), the 4th Regiment of Moroccan Spahis (4e RSM) (light tank), the 2nd Group of Moroccan Tabors (2e GTM), the Commandos de Choc battalion and the 3rd Battalion, 69th Mountain Artillery Regiment (69e RAM),Grandes Unités Françaises, Vol. IV, p. 422 landed on Fascist-occupied Corsica in the same month. To the south, the German 90. Panzergrenadier-Division and the Reichsführer-SS assault infantry brigade were evacuating Sardinia and landing on the southern coast of Corsica. Wishing to cut off the German troops, and informed on September 10, 1943, that the Royal Italian Army troops on Corsica were willing to fight on the side of the Allies, the French launched Operation Vésuve and landed elements of the 1st Army Corps at Ajaccio on September 13, meeting Corsican partisans who also wanted enemy troops off the island.

German General Fridolin von Senger und EtterlinFridolin von Senger und Etterlin, 1891–1963, commander of 17. Panzer-Division and military commander of Sicily prior to becoming military commander for Sardinia and Corsica in 1943. Went on to command XIV. Panzerkorps in Italy 1943–1945, prisoner of war 1945–1948. hoped to obtain reinforcements with which to hold the island. After the Germans began disarming Italian soldiers, General MagliGiovanni Magli, 1884–1969, commander of the Centauro Armored Division prior to commanding VII Army Corps on Corsica, then GOC of Sardinia 1943–1944. of the Italian Army ordered Italian forces to consider the Germans as an enemy rather than as allies. Thereafter, Italian units on the island cooperated with the French forces. Surprising the Italian Friuli Division in the northern port of Bastia on the night of September 13, 1943, the SS troops took 2,000 Italian prisoners and secured the port from which the Germans could evacuate their forces. Although supported by the Royal Navy, the French were unable to land forces quickly enough on Corsica to prevent the bulk of the German troops from reaching their exit ports on the east coast of the island. The final combat took place around Bastia, with the island secured by French forces on October 4, 1943. The bulk of the German forces had made good their escape. The Germans took 700 casualties and lost 350 men to POW camps. The Italians lost 800 men in the fighting (mostly Friuli Division troops), and the French had 75 killed, 12 missing, and 239 wounded.L'Armée de la Victoire, Vol. I, p. 161 From October 1943 until May 1944, the 1st Army Corps defended Corsica, conducted training, and moved units between Corsica and North Africa. On April 18, 1944, the 1st Army Corps was subordinated to General de Lattre'sJean Joseph Marie Gabriel de Lattre de Tassigny, 1889–1952, commander of the 14e DI, 13th Military Division, 14th Military Division, and CinC Tunisia prior to commanding Armée B. Postwar, became high commissioner then CinC for French Indochina. Armée B.

Elba 1944

Following the liberation of Corsica, the French proposed to invade the island of Elba, possession of which would allow the Allies to dominate by gunfire ships in the Piombino Channel and vehicles on the coastal road of the Italian Peninsula, both transportation arteries essential to the supply of German Wehrmacht forces in western Italy. Initially, the proposal was denied by General Eisenhower,Dwight David Eisenhower, 1890-1969, Commander in Chief Allied Expeditionary Force Mediterranean, then Commander in Chief Supreme Headquarters Allied Expeditionary Force in 1944–1945, postwar U.S. Army Chief of Staff and President of the United States. who considered it a dispersal of resources while the planning for the Anzio landings was underway. After British General Sir Henry Maitland WilsonHenry Maitland Wilson, Baron Wilson of Libya & of Stowlangtoft, 1881–1964, commander of 2nd Division, British forces in Egypt, W Force, GOC Palestine and Transjordan, commander of 9th Army, and CinC of Persia and Iraq and then Middle East Command prior to becoming Supreme Allied Commander Mediterranean in 1944. Postwar was the Head of the British Joint Staff Mission to Washington. took over the Mediterranean Theater, however, attitudes at Allied headquarters changed and the operation was approved.The History of the French First Army, p.34 By this time, though, the Germans had strongly fortified Elba, an island dominated by rugged terrain in any case, making the assault considerably more difficult.

At 0400 hours on June 17, 1944, the 1st Army Corps assaulted Elba in Operation Brassard. French forces comprised the 9th Colonial Infantry Division (9e DIC), two battalions of French commandos (Commandos d'Afrique and Commandos de Choc), a battalion and supplementary battery of the Colonial Artillery Regiment of Morocco (R.A.C.M.) and the 2nd Group of Moroccan Tabors (2e GTM), in addition to 48 men from "A" and "O" commandos of the Royal Navy.BBC – WW2 People's War – Operation Brassard The Invasion of Elba French Choc (lightly armed fighters who had the mission of operating behind enemy lines) units landed at multiple points before the main landing force and neutralized coastal artillery batteries. Landing in the Gulf of Campo on the south coast, the French initially ran into difficulties because of the German fortifications and extremely rugged terrain that ringed the landing area. Falling back on an alternate plan, the landing beach was shifted to the east, near Nercio, and here the troops of the 9th Colonial Infantry Division seized a viable beachhead. Within two hours, French commandos reached the crest of the 400-meter Monte Tambone Ridge overlooking the landing areas. The RN commandos boarded and seized the German Flak ship Köln and also landed to guide in other troops headed for the beaches, but a massive blast from a German demolition charge killed 38 of their men. Portoferraio was taken by the 9th Division on June 18 and the island was largely secured by the following day. Fighting in the hills between the Germans and the Senegalese colonial infantry was vicious, with the Senegalese employing flamethrowers to clear entrenched German troops.The History of the French First Army, p.45