The First Army () was a field army of France that fought during World War I and World War II. It was also active during the Cold War. First World War On mobilization in August 1914, General Auguste Dubail was put in the charge of the First Army, which comprised the 7th, 8th, 13th, 14th, and 21st Army Corps, two divisions of cavalry and one reserve infantry division. It was massed between Belfort and the general line Mirecourt-Lunéville with headquarters at Epinal. First Army then took part, along with the French Second Army, in the Invasion of Lorraine. The First Army intended to take the strongly defended town of Sarrebourg. Bavarian Crown Prince Rupprecht, commander of the German Sixth Army, was tasked with stopping the French invasion. The French attack was repulsed by Rupprecht and his stratagem of pretending to retreat and then strongly attacking back. On 20 August Rupprecht launched a major counter-offensive, driving the French armies out. Dubail was replaced in 1915. A frantic 1916 saw four different commanders command the First Army; an even more frantic 1917 saw five different commanders at the helm (including François Anthoine during the Battle of Passchendaele). By the time of Passchendaele, the French First Army was composed of two corps - the 1st Army Corps (composed of 4 divisions) and the 36th Army Corps (composed of 2 divisions). Second World War 1940 During the Second World War the French First Army, under the command of General Georges Blanchard, formed part of the forces ranged against the German Army during the Battle of France. On 10 May 1940, it included the Cavalry Corps, and the 3rd, 4th, and 5th Army Corps, as well as the 1re Division Cuirassée (1st DCR, effectively an armoured division with four battalions of tanks and one of infantry, plus supporting units) and 32nd Infantry Division. When the Wehrmacht invaded France and the Low Countries in 1940, the First Army was one of the many armies including the British Expeditionary Force (BEF) that advanced north to stop the German armies. On 21 May 1940 the First Army was one of the armies trapped in a vast pocket with their backs to the sea that would eventually result in the Dunkirk evacuations. As the Germans moved in, what remained of the once-formidable First Army was hopelessly surrounded at Lille but counterattacked and resisted fiercely in a delaying action aiming