Great Retreat The Great Retreat , also known as the Retreat from Mons , is the name given to the long , fighting retreat by Allied forces to the River Marne , on the Western Front early in World War I , after their holding action against the Imperial German Armies at the Battle of Mons on 23 August 1914 . The Allies were closely pursued by the Germans , acting under the Schlieffen Plan . Le Cateau . The Allies retreated from Mons , past Maubeuge ( which fell to the Germans on 7 September after a successful siege ) , and the British troops were supposed to meet at the town of Le Cateau - Cambrésis ( usually referred to as just Le Cateau ) . However , I Corps under Douglas Haig did not reach Le Cateau , getting no nearer than Landrecies . Thus a gap of some miles was opened up between I and II Corps . Several days were to pass before the two corps were reunited . On the evening of 25 August , British II Corps commander General Horace Smith - Dorrien was faced with the prospect that , if his exhausted troops continued to retreat , they would be enveloped in a piecemeal fashion . He therefore ordered his corps to stand and fight to deliver a ' stopping blow ' to the Germans . The Allies set up defensive positions near the town and prepared for the inevitable attack . As Haig ' s I Corps had not arrived , Smith - Dorrien ' s right flank was ' in the air ' ( unprotected ) . On the morning of the 26th , the Germans launched a heavy assault on the British positions , and the Battle of Le Cateau began . The four British divisions were attacked by six German ones . Using similar tactics to those used at Mons the British regulars were able to hold their own ; rapid rifle and artillery fire inflicted heavy losses on the advancing Germans . However , when two more German divisions joined the battle , II Corps came close to defeat . By the afternoon , both British flanks began to break and the order to withdraw was given . Envelopment was prevented by the arrival of General Sordet ’ s French Cavalry Corps on the British left . Smith - Dorrien ' s decision to turn and fight the Germans at Le Cateau was vindicated . The Germans suffered heavy casualties and another delay was imposed on their timetable , also Haig ' s I Corps was able to break away from the Germans . However , the disagreement between Sir John French ( who had opposed the action ) and Smith - Dorrien was to have consequences in the coming months . Of the 40 , 000 Allied troops fighting at Le Cateau , 7 , 812 were killed , captured or wounded . Many British units had disappeared from the rolls altogether . About 2 , 600 men became prisoners of war , although in one extravagant German account it is suggested that 12 , 000 prisoners had been taken . Thirty eight British artillery guns were also lost . Some senior British losses at Le Cateau were Lt - Col Charles Brett , CO 2nd Suffolks , Lt - Col Alfred Dykes , CO 1st King ' s Own , and Lt - Col Edward Panter - Downes , CO 2nd Royal Irish Regiment , who were all killed in action . Although none of the men have a known grave , all are commemorated on the La Ferté - sous - Jouarre memorial to the missing . As the retreat continued south towards Paris , there were a number of small but vigorous holding actions by various units of the British rearguard : St . Quentin . With retreat all long the line , the commander - in - chief of the French forces , Joseph Joffre , held off the German advance through counterattacking . This was only done with the help of the Fifth Army under Charles Lanrezac . The BEF was also involved , although not in a way one might expect . A cavalry officer , Major Tom Bridges , on riding into the town , was horrified to learn of the near disintegration of units in the British 4th Division . Exhausted men were sleeping in the streets of St . Quentin ; officers had escaped by train to Paris . With such an air of defeat in the town , Bridges decided that something must be done and came up with the notion of music . Lacking a band , he went to a toyshop and bought a drum and a penny whistle . Giving the whistle to his trumpeter , he proceeded to the town square and beat out the time for ' The British Grenadiers ' , while the trumpeter accompanied him . The watching soldiers , while thinking him mad , formed up and continued the retreat . On 29 August , the French Fifth Army attacked St . Quentin with its full force . Possessing orders captured with a French officer , Bülow was already aware of the counter - offensive and had time to prepare . The attacks against the town by the eighteenth corps met with heavy casualties and little success , but the tenth and third corps on the right flank was rallied by the commander of the first corps , Franchet d ' Esperey . Advances on the right were made successfully against the Germans with Guise falling back , in addition to units of the Guard Corps and Bülow ' s elite . The next day , the French continued the retreat back to the Marne , with the Germans refraining from following . The Marne . The Allied retreat finally ended at the River Marne where they prepared to make a stand to defend Paris . This led to the First Battle of the Marne , which was fought from 5 to 12 September 1914 . This battle would prove to be a major turning point of the war by denying the Germans an early victory . Field Marshal John French , commander of the British Expeditionary Force , began to make contingency plans for a full retreat to the ports on the English Channel followed by an immediate British evacuation . The French Military Governor of Paris , General Joseph Gallieni , was tasked with the defence of the city . He wanted to organise the French and British armies to counter the weight of the German advance . So , after consulting with Lord Kitchener , Gallieni managed to secure overall command of the BEF , and ordered Field Marshal French not to withdraw to the channel . Gallieni ' s plan was a very simple one : All allied units would counter - attack the Germans along the Marne , hopefully halting their advance . As this was going on , allied reserves would be thrown in to restore the ranks and attack the German flanks . At noon on 5 September , the battle commenced when the French 6th Army , led by General Michel - Joseph Maunoury , accidentally stumbled into the forward guard of the German 1st Army under General Alexander von Kluck . The British avoided joining the battle until von Kluck made a grave tactical error on 9 September 1914 . Von Kluck commanded his forces to pursue and annihilate the French 6th Army as the latter retreated back towards the Marne . This command opened a 50 km gap between the German 1st and 2nd Armies on his right flank , a gap discovered by allied observation aircraft . The Allied forces quickly exploited this tactical error by attacking the flanks of both German armies , using the entire BEF as well as the French 5th Army . German Chief of the General Staff Helmuth von Moltke suffered a nervous breakdown upon learning about the gravity of the error . His subordinates assumed command over the two flanked armies , which were withdrawn to regroup at the Aisne River . Von Moltke is said to have reported to the Kaiser : " Your Majesty , we have lost the war . " The total British casualties amounted to 1 , 701 of all ranks , killed , wounded or missing between 6 September and 10 September . Some notable casualties for the British Army were Brig . - Gen . Neil Findlay , CRA 1st Division , who died as a result of wounds received on 10 September 1914 and is buried at Vailly British Cemetery and Lt - Col Guy Knight , OC 1st Loyal North Lancs . Knight died the next day and was buried at Priez Communal Cemetery . The German retreat between 9 September and 13 September signaled the abandonment of the Schlieffen Plan . In the battle ' s aftermath , both sides dug in for trench warfare and four years of grueling stalemate ensued . The defeat of the German Army on the River Marne was decisive . Their war plan , to quickly overcome France before turning attentions to Russia , had come to nothing despite the enormous efforts expended . It has sometimes been argued that Germany could no longer win the war after their defeat on the Marne in 1914 . Around six hundred Paris taxicabs , mainly Renault AG , were commandeered by Gallieni and used to transport six thousand French reserve infantry troops from the seventh division to the battle . The tables were now turned with the Allies pursuing the retreating Germans . Their next major clash was to be the First Battle of the Aisne .