The Race to the Sea (; , ) took place from 17 September to 19 October 1914 during the First World War, after the Battle of the Frontiers () and the German advance into France. The invasion had been stopped at the First Battle of the Marne and was followed by the First Battle of the Aisne a Franco-British counter-offensive. The term describes reciprocal attempts by the Franco-British and German armies to envelop the northern flank of the opposing army through the provinces of Picardy, Artois and Flanders, rather than an attempt to advance northwards to the sea. The "race" ended on the North Sea coast of Belgium around 19 October, when the last open area from Diksmuide to the North Sea was occupied by Belgian troops who had retreated after the Siege of Antwerp (28 September – 10 October). The outflanking attempts had resulted in a number of encounter battles but neither side was able to gain a decisive victory.
After the opposing forces had reached the North Sea, both tried to conduct offensives leading to the mutually costly and indecisive Battle of the Yser from 16 October to 2 November and the First Battle of Ypres from 19 October to 22 November. After mid-November, local operations were carried out by both sides and preparations were made to take the offensive in the spring of 1915. Erich von Falkenhayn, Chief of the German General Staff ( OHL) since 14 September, concluded that a decisive victory could not be achieved on the Western Front and that it was equally unlikely in the east. Falkenhayn abandoned (strategy of annihilation) and attempted to create the conditions for peace with one of Germany's enemies, by (strategy of exhaustion), to enable Germany to concentrate its resources decisively to defeat the remaining opponents.
Over the winter lull, the French army established the theoretical basis of offensive trench warfare, originating many of the methods which became standard for the rest of the war. Infiltration tactics, in which dispersed formations of infantry were followed by (trench cleaners), to capture by-passed strong points were promulgated. Artillery observation from aircraft and creeping barrages, were first used systematically in the Second Battle of Artois from 9 May to 18 June 1915. Falkenhayn issued memoranda on 1915, to govern defensive battle on the Western Front, in which the existing front line was to be fortified and to be held indefinitely with small numbers of troops, to enable more divisions to be sent to the Eastern Front. New defences were to be built behind the front line to contain a breakthrough until the position was restored by counter-attacks. The began the huge task of building field fortifications, which were not complete until the autumn of 1915.
Background Strategic developments
Plan XVII
Under Plan XVII the French peacetime army was to form five field armies, with groups of Reserve divisions attached and a group of reserve divisions was to assemble on each flank, men. The armies were to concentrate opposite the German frontier around Épinal, Nancy and Verdun–Charleville-Mezières, with an army in reserve around Sainte-Menehould and Commercy. Since 1871 railway building had given the French General Staff sixteen lines to the German frontier against thirteen available to the German army and the French could wait until German intentions were clear. The French deployment was intended to be ready for a German offensive in Lorraine or through Belgium. It was anticipated that the Germans would use reserve troops but also expected that a large German army would be mobilised on the border with Russia, leaving the western army with sufficient troops only to advance through Belgium south of the Meuse and the Sambre rivers. French intelligence had obtained a map exercise of the German general staff of 1905, in which German troops had gone no further north than Namur and assumed that plans to besiege Belgian forts were a defensive measure against the Belgian army.
A German attack from south-eastern Belgium towards Mézières and a possible offensive from Lorraine towards Verdun, Nancy and St. Dié was anticipated; the plan was an evolution from Plan XVI and made more provision for the possibility of a German offensive through Belgium. The First, Second and Third Armies were to concentrate between Épinal and Verdun, opposite Alsace and Lorraine. The Fifth Army was to assemble from Montmédy to Sedan and Mézières and the Fourth Army was to be held back west of Verdun, ready to move east to attack the southern flank of a German invasion through Belgium or southwards against the northern flank of an attack through Lorraine. No formal provision was made for combined operations with the British Expeditionary Force (BEF) but joint arrangements had been made and in 1911 during the Second Moroccan Crisis the French had been told that six divisions could be expected to operate around Maubeuge.
Schlieffen–Moltke Plan
German strategy had given priority to offensive operations against France and a defensive posture against Russia since 1891. German planning was determined by numerical inferiority, the speed of mobilisation and concentration and the effect of the vast increase of the power of modern weapons. Frontal attacks were expected to be costly and protracted, leading to limited success, particularly after the French and Russians modernised their fortifications on the frontiers with Germany. Alfred von Schlieffen, Chief of the Imperial German General Staff, OHL () from 1891 to 1906, devised plans to evade the French frontier fortifications with an offensive on the flank, which would have a local numerical superiority and obtain rapidly a decisive victory. By 1906, such a manoeuvre was intended to pass through neutral Belgium and threaten Paris from the north. Helmuth von Moltke the Younger succeeded Schlieffen in 1906 and was less certain that the French would conform to German assumptions. Moltke adapted the deployment and concentration plan to accommodate an attack in the centre or an enveloping attack from both flanks as variants to the plan, adding divisions to the left flank opposite the French frontier, from the expected to be mobilised in the (western army). The main German force would still advance through Belgium and attack southwards into France, the French armies would be enveloped on the left and pressed back over the Meuse, Aisne, Somme, Oise, Marne and Seine, unable to withdraw into central France. Either the French would be annihilated or the manoeuvre from the north would create conditions for victory in the centre or in Lorraine on the common border.
Battle of the Frontiers, 7 August – 13 September
The Battle of the Frontiers is a general name for all of the operations of the French armies until the Battle of the Marne. A series of encounter battles began between the German, French and Belgian armies, on the German-French frontier and in southern Belgium on 4 August 1914. The Battle of Mulhouse (Battle of Alsace ) was the first French offensive against Germany. The French captured Mulhouse until forced out by a German counter-attack on 11 August and fell back toward Belfort. The main French offensive, the Battle of Lorraine , began with the Battles of Morhange and Sarrebourg () advances by the First Army on Sarrebourg and the Second Army towards Morhange. Château-Salins near Morhange was captured on 17 August and Sarrebourg the next day. The German 6th Army and 7th Army counter-attacked on 20 August and the Second Army was forced back from Morhange and the First Army was repulsed at Sarrebourg. The German armies crossed the border and advanced on Nancy but were stopped to the east of the city.
To the south the French retook Mulhouse on 19 August and then withdrew. On 24 August, at the Battle of the Mortagne a limited German offensive in the Vosges, the Germans managed a small advance, before a French counter-attack retook the ground. By 20 August, a German counter-offensive in Lorraine had begun and the German 4th Army and 5th Army advanced through the Ardennes on 19 August towards Neufchâteau. An offensive by French Third and Fourth Armies through the Ardennes began on 20 August, in support of the French invasion of Lorraine. The opposing armies met in thick fog and the French mistook the German troops for screening forces. On 22 August, the Battle of the Ardennes began with French attacks, which were costly to both sides and forced the French into a disorderly retreat late on 23 August. The Third Army recoiled towards Verdun, pursued by the 5th Army and the Fourth Army retreated to Sedan and Stenay. Mulhouse was recaptured again by German forces and the Battle of the Meuse caused a temporary halt of the German advance.
Liège was occupied by the Germans on 7 August, the first units of the BEF landed in France and French troops crossed the German frontier. On 12 August, the Battle of Haelen was fought by German and Belgian cavalry and infantry and was a Belgian defensive success. The BEF completed its move of four divisions and a cavalry division to France on 16 August, as the last Belgian fort of the Fortified Position of Liège surrendered. The Belgian government withdrew from Brussels on 18 August and the German army attacked the Belgian field army at the Battle of the Gete. Next day the Belgian army began to retire towards Antwerp, which left the route to Namur open; Longwy and Namur were besieged on 20 August. Further west the Fifth Army had concentrated on the Sambre by 20 August, facing north either side of Charleroi and east towards the Belgian Fortified Position of Namur. On the left, the Cavalry Corps (General André Sordet) linked with the BEF at Mons.
The Fifth Army was confronted by the German 3rd Army and 2nd Army from the east and the north. Before the Fifth Army could attack over the Sambre the 2nd Army attacked at the Battle of Charleroi and at Namur on 21 August. The 3rd Army crossed the Meuse and attacked the French right flank and on 23 August, the Fifth Army began a retirement southwards to avoid encirclement. After the Battle of St. Quentin, the French withdrawal continued. On 22 August, the BEF advanced and on 23 August fought the Battle of Mons, a delaying action against the German 1st Army, to protect the left flank of the French Fifth Army. The BEF was forced to retreat when the 1st Army began to overrun the British defences on the right flank and the Fifth Army retired from the area south of the Sambre, exposing the British right flank to envelopment. Namur capitulated on 25 August and a Belgian sortie from Antwerp led to the Battle of Malines
After the French defeat during the Battle of Lorraine, the French Second Army retreated to the Grand Couronné heights near Nancy and dug in, on an arc from Pont-à-Mousson to Champenoux, Lunéville and Dombasle-sur-Meurthe by 3 September. The Battle of Grand Couronné (4–13 September) began next day, when the German 7th and 6th Armies attacked simultaneously at St. Dié and Nancy, as the Second Army sent reinforcements to the Third Army. Costly fighting continued until 12 September but the French were able to withdraw more than four corps to reinforce the armies on the left flank. On 13 September, Pont-à-Mousson and Lunéville were recaptured by the French and the advance continued close to the Seille river, where the front stabilised. The battles kept a large number of German troops in Lorraine, as the Great Retreat further west culminated on the Marne.
The Great Retreat, 24 August – 5 September