Race to the Sea in the context of "Méteren"

The Western Front was one of the main theatres of war during World War I. Following the outbreak of war in August 1914, the German Army opened the Western Front by invading Luxembourg and Belgium, then gaining military control of important industrial regions in France. The German advance was halted with the Battle of the Marne. Following the Race to the Sea, both sides dug in along a meandering line of fortified trenches, stretching from the North Sea to the Swiss frontier with France, the position of which changed little except during early 1917 and again in 1918.

Between 1915 and 1917 there were several offensives along this front. The attacks employed massive artillery bombardments and massed infantry advances. Entrenchments, machine gun emplacements, barbed wire, and artillery repeatedly inflicted severe casualties during attacks and counter-attacks and no significant advances were made. Among the most costly of these offensives were the Battle of Verdun, in 1916, with a combined 700,000 casualties, the Battle of the Somme, also in 1916, with over a million casualties, and the Battle of Passchendaele, in 1917, with 487,000 casualties.

Trench warfare is a type of land warfare using occupied lines largely comprising military trenches, in which combatants are well-protected from the enemy's small arms fire and are substantially sheltered from artillery. It became archetypically associated with World War I (1914–1918), when the Race to the Sea rapidly expanded trench use on the Western Front starting in September 1914.

Trench warfare proliferated when a revolution in firepower was not matched by similar advances in mobility, resulting in a grueling form of warfare in which the defender held the advantage. On the Western Front in 1914–1918, both sides constructed elaborate trench, underground, and dugout systems opposing each other along a front, protected from assault by barbed wire. The area between opposing trench lines (known as "no man's land") was fully exposed to artillery fire from both sides. Attacks, even if successful, often sustained severe casualties.

The Great Retreat (French: Grande Retraite) also known as the retreat from Mons, took place in the First World War. The retreat was more than 200 km (120 mi), from Belgium to the River Marne in France in August and September 1914. The French Fifth Army and the British Expeditionary Force had been defeated by the armies of the German Empire 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, 29–30 August) failed to halt the German advance. The retreat of the Fifth Army and the BEF continued to the south side of the Marne River. From 5 to 12 September, the First Battle of the Marne ended the Allied retreat and forced the German armies to retire towards the Aisne River and to fight the First Battle of the Aisne (13–28 September). Reciprocal attempts to outflank the opposing armies to the north known as the Race to the Sea followed from 17 September to 17 October.

The First Battle of Ypres (French: Première Bataille des Flandres, German: Erste Flandernschlacht, 19 October – 22 November 1914) was a battle of the First World War, fought on the Western Front around Ypres, in West Flanders, Belgium. The battle was part of the First Battle of Flanders, in which German, French, Belgian armies and the British Expeditionary Force (BEF) fought from Arras in France to Nieuwpoort (Nieuport) on the Belgian coast, from 10 October to mid-November. The battles at Ypres began at the end of the Race to the Sea, reciprocal attempts by the German and Franco-British armies to advance past the northern flank of their opponents. North of Ypres, the fighting continued in the Battle of the Yser (16–31 October), between the German 4th Army, the Belgian army and French marines.

The fighting has been divided into five stages, an encounter battle from 19 to 21 October, the Battle of Langemarck from 21 to 24 October, the battles at La Bassée and Armentières to 2 November, coincident with more Allied attacks at Ypres and the Battle of Gheluvelt (29–31 October), a fourth phase with the last big German offensive, which culminated at the Battle of Nonne Bosschen on 11 November, then local operations which faded out in late November. Brigadier-General James Edmonds, the British official historian, wrote in the History of the Great War, that the II Corps battle at La Bassée could be taken as separate but that the battles from Armentières to Messines and Ypres, were better understood as one battle in two parts, an offensive by III Corps and the Cavalry Corps from 12 to 18 October against which the Germans retired and an offensive by the German 6th Army and 4th Army from 19 October to 2 November, which from 30 October, took place mainly north of the Lys, when the battles of Armentières and Messines merged with the Battles of Ypres.

The Territorial Force was a part-time volunteer component of the British Army, created in 1908 to augment British land forces without resorting to conscription. The new organisation was create by the Territorial and Reserve Forces Act 1907 (7 Edw. 7. c. 9), which consolidated the 19th-century Volunteer Force and yeomanry into a unified auxiliary, commanded by the War Office and administered by local county territorial associations. The Territorial Force was designed to reinforce the regular army in expeditionary operations abroad, but because of political opposition it was assigned to home defence. Members were liable for service anywhere in the UK and could not be compelled to serve overseas unless they volunteered to do so.

In the first two months of the First World War, territorials volunteered for foreign service in significant numbers, allowing territorial units to be deployed abroad. They saw their first action on the Western Front during the initial German offensive of 1914, and the force filled the gap between the near destruction of the regular army that year and the arrival of the New Army in 1915. Territorial units were deployed to Gallipoli in 1915 and, following the failure of that campaign, provided the bulk of the British contribution to allied forces in the Sinai and Palestine Campaign. By the war's end, the Territorial Force had fielded twenty-three infantry divisions and two mounted divisions on foreign soil. It was demobilised after the war and reconstituted in 1921 as the Territorial Army by the Territorial Army and Militia Act 1921 (11 & 12 Geo. 5. c. 37).