The Great War exploded in the summer of 1914 as Germany marched into Belgium, sweeping aside Allied forces in pursuit of the crushing victory they expected with their finely tuned, but heavily modified, Schlieffen Plan. The German army then pushed on into France and as its columns closed in on Paris, victory seemed a foregone conclusion. However, defying all odds, the weary French and British made an about face and counterattacked along the Marne, defeating the Schlieffen Plan and halting the German advance.