The Great Retreat, also known as the Retreat from Mons, is the name given to the long withdrawal to the River Marne, in August and September 1914, by the British Expeditionary Force (BEF) and the French Fifth Army, Allied forces on the Western Front in World War I, after their defeat by the Imperial German armies at the Battle of Charleroi (21 August) and the Battle of Mons (23 August). A counter-offensive by the Fifth Army, with some assistance from the BEF at the First Battle of Guise (Battle of St. Quentin failed to end the German advance and the Franco-British retreat continued to and beyond the Marne. From the First Battle of the Marne ended the Allied retreat and forced the German armies to retire towards the Aisne river and fight the First Battle of the Aisne  Reciprocal attempts to outflank the opposing armies to the north followed, known as the Race to the Sea