Great Retreat

Significance

The Great Retreat, also known as the retreat from Mons, followed the defeat of the French Fifth Army and the British Expeditionary Force at the Battle of Charleroi and the Battle of Mons. Covering more than 200 km from Belgium to the River Marne in France across August and September 1914, it represented a critical early crisis for the Allied cause on the Western Front. A counter-offensive at the First Battle of Guise failed to arrest the German advance, forcing continued withdrawal to the south bank of the Marne. The retreat ended only when the First Battle of the Marne, fought 5–12 September, halted the German drive and compelled German armies to fall back toward the Aisne River. This sequence directly produced the First Battle of the Aisne and the subsequent Race to the Sea, in which both sides attempted to outflank each other to the north from 17 September to 17 October, ultimately setting the conditions for the static trench warfare that defined the Western Front for the remainder of the war.

Forces & casualties