The Allied supreme commander General Maurice Gamelin committed his First Army Group, under General Gaston Billotte, and its strongest Army, the French 1st Army under General Georges Blanchard with the fully mechanised Corps de Cavalerie (Cavalry Corps), commanded by General René Prioux, to advance into Belgium to support the large but more lightly equipped Belgian Army.
Den allierede overgeneral Maurice Gamelin gav sin første armegruppe under general Gaston Billotte, og dens stærkeste arme, den 1. franske arme med det fuldt mekaniserede Corps de Cavalerie under ledelse af general René-Jacques-Adolphe Prioux, til opgave at rykke ind i Belgien for at støtte den store men lettere udstyrede belgiske arme.