With the German invasion of France and the low countries on 10 May 1940 the BEF advanced into Belgium to meet the advancing German forces. Stationed to the south in front of the Maginot Line, the 51st Division was not a part of the force involved in Belgium, and was thus not involved in the Dunkirk evacuation. In response to the German advance it was pulled back to form a defensive line along the Somme, where it was attached to the French Tenth Army. With the withdrawal of Allied forces at Dunkirk, the Germans turned their attention to the south.