day. The German 6th Army and 7th Army counter-attacked on 20 August and the Second Army was forced back from Morhange and the First Army was repulsed at Sarrebourg. The German armies crossed the border and advanced on Nancy but were stopped to the east of the city. To the south the French retook Mulhouse on 19 August and then withdrew. On 24 August at the Battle of the Mortagne a limited German offensive in the Vosges, the Germans managed a small advance, before a French counter-attack retook the ground. By 20 August a German counter-offensive in Lorraine had begun and the German 4th Army and 5th Army advanced through the Ardennes on 19 August towards Neufchâteau. An offensive by French Third and Fourth Armies through the Ardennes began on 20 August, in support of the French invasion of Lorraine. The opposing armies met in thick fog and the French mistook the German troops for screening forces. On 22 August the Battle of the Ardennes began with French attacks, which were costly to both sides and forced the French into a disorderly retreat late on 23 August. The Third Army recoiled towards Verdun, pursued by the 5th Army and the Fourth Army retreated to Sedan and Stenay. Mulhouse was recaptured again by German forces and the Battle of the Meuse caused a temporary halt of the German advance. Liège was occupied by the Germans on 7 August, the first units of the BEF landed in France and French troops crossed the German frontier. On 12 August the Battle of Haelen was fought by German and Belgian cavalry and infantry and was a Belgian defensive success. The BEF completed its move of four divisions and a cavalry division to France on 16 August, as the last Belgian fort of the Fortified Position of Liège surrendered. The Belgian government withdrew from Brussels on 18 August and the German army attacked the Belgian field army at the Battle of the Gete. Next day the Belgian army began to retire towards Antwerp, which left the route to Namur open; Longwy and Namur were besieged on 20 August. Further west the Fifth Army had concentrated on the Sambre by 20 August, facing north either side of Charleroi and east towards the Belgian Fortified Position of Namur. On the left, the Cavalry Corps (General André Sordet) linked with the BEF at Mons. The Fifth Army was