The Battle of the Frontiers had been a catastrophe for France, and by the end of August the situation for the Allies was critical. Everywhere, their armies were in retreat, and the steadily advancing German columns had produced panic within government circles in Paris, who was preparing for a siege. French troops were exhausted from their retreat to the south of the Marne River. However, General Joseph Joffre, the French commander in chief, set a new plan in action, and as an initial step, he switched forces from eastern France, to form the new French Sixth Army for deployment on the western front. On the morning of September 6, the French 6th Army attacked the flank of the German Fist Army. The German’s shock left them vulnerable as a 30-mile-wide gap was opened between the First Army troops and the German Second Army. The Allies immediately exploited the gap and prime opportunity and Allied troops swarmed in. The battle was a victory for the Allies, but ultimately led to four years of trench warfare stalemate on the Western Front.