During the Battles of St. Quentin and Guise, the 1st Corps forced Karl von Bülow's German Second Army into retreat in what historian Stuart Robson called "the last old-style Napoleonic infantry charge in history."

[4] 1st Army Corps was constituted on August 27, 1939, in Lille under the command of Major General Sciard[5] as part of the French mobilization for war.

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.

[7] The period from May 19–26 saw the corps falling back to the line of the river Somme, where the French Army intended to make a major stand.

From June 9, the corps was involved in a succession of withdrawals that were meant to form lines of defense along the rivers Avre, Oise, Nonette, Seine, and Loire.

[9] 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.

Now commanded by Lieutenant General Martin[11] the primary combat units of the corps were provided American equipment and weapons as part of the rearmament of the French Army of Africa.

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.

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.

After British General Sir Henry Maitland Wilson[18] took over the Mediterranean Theater, however, attitudes at Allied headquarters changed and the operation was approved.

[19] 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.

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.

1st Army Corps was now under the command of Lieutenant General Émile Béthouart,[22] a veteran of the 1940 campaign in Norway and an officer who had actively assisted the Allied landings in French North Africa in November 1942.

In mid-September, the corps secured the Lomont Mountains, a range about 130 kilometers (81 mi) long running from the river Doubs to the Swiss border.

German resistance was spotty in September, but rapidly coalesced in front of the Belfort Gap, a corridor of relatively flat terrain that lies between the Vosges and Jura mountains on the Swiss frontier, and a gateway to the river Rhine.

Operating with one division and experiencing the same logistics problems as other Allied units in Europe, the advance of the 1st Army Corps was slowed in front of the Belfort Gap by the German 11.

Compounding the distance that supplies had to travel from the ports in southern France were the north–south railway lines with destroyed bridges and sections of track.

All of these factors served to force a halt to the 1st Army Corps' advance in October while the corps improved its supply situations and resolved manpower issues caused by the French high command's decision to rotate the Senegalese troops to the south and replace them with French Forces of the Interior manpower.

By a stroke of fate, the French attack caught the German division commander near the front lines, who perished under a hail of Moroccan gunfire.

[25] French losses, however, had also been significant, and plans to immediately clear the Alsatian Plain of German forces had to be shelved while both sides gathered strength for the next battles.

Seventh Army had collapsed the German presence in Alsace to a roughly circular pocket around the town of Colmar on the Alsatian Plain.

By the end of the month, however, other attacks by U.S. and French forces against the Colmar Pocket had forced the Germans to redistribute their troops, and an early February attack by the 1st Army Corps moved north through weak German resistance, reaching the bridge over the Rhine at Chalampé and making contact with the U.S. XXI Corps at Rouffach, south of Colmar.

Thereafter, the thrust of the Allied offensive moved to the north, and the 1st Army Corps was assigned the defense of the Rhine from the area south of Strasbourg to the Swiss frontier until mid-April 1945.

Frantic attempts at escape by the encircled German troops came to naught among French roadblocks and the formidable terrain of the forest, and they were left no options save death or surrender.

Elements of the 5e DB and the 4e DMM drove southeast along the north shore of Lake Constance, capturing Bregenz and then turning east toward Sankt-Anton.