Area of operations British Expeditionary Force (World War I)

1 area of operations

1.1 1914
1.2 1915
1.3 1916
1.4 1917
1.5 1918

area of operations
1914

the race sea, allied front line , movements shown in red, german front line , movements shown in blue

the british army first engaged german army in battle of mons on 23 august 1914, part of greater battle of frontiers. massed rifle fire of professional british soldiers inflicted heavy casualties on germans attacked en masse on terrain devoid of cover. british held german advance until evening when began retiring second defensive line in retreat mons during engaged in battle of le cateau. following british defeat @ le cateau, bef retreated unmolested germans further 5 days, retreating full 400 km in thirteen days.

the allied retreat ended @ river marne, entente forces prepared make stand defend paris. led first battle of marne, fought 5 10 september 1914. battle prove major turning point of war: denied germans victory. 13 september first battle of aisne took place, both sides starting dig trenches. three-week period following development of trench warfare each side gave frontal assaults , began trying encircle each other s flank. period became known race sea: germans aimed turn allied left flank, , allies sought turn german right flank.

the front line in 1916, british gains during battle of somme shaded blue.

by end of first battle of ypres both sides started dig in , trench warfare replaced manoeuvre warfare had featured during race sea. continuous trench lines of western front stretched 400 miles (640 km) north sea swiss frontier. british army held small portion of 400 mile front: north of pre-war belgium border river somme in france, varying in length 20 miles (32 km) in 1914, on 120 miles (190 km) in 1918, in area commonly known flanders.

1915

from end of 1914, , in 1915, bef attacks centred around ypres salient. in september 1915, 6 divisions took part in battle of loos – notable first use of poison gas british.

the french, british, belgian , american lines of attack, during hundred days offensive


1916

in 1916 bef had moved picardy region of france. battle of somme dominated british military activity year. allied forces attempted break through german lines along 25 miles (40 km) front north , south of river somme in northern france. on first day on somme bef suffered 59,000 casualties. after war final tally counted 419,654 british , 204,253 french killed, wounded, or taken prisoner; of 623,907 total casualties, 146,431 either killed or missing.

1917

in 1917 bef s attacks moved along front, operated in pas-de-calais during battle of arras. concentrated in belgium battle of messines , battle of passchendale, , ended year in pas-de-calais battle of cambrai.

1918

in spring of 1918 bef came under attack both in flanders , on somme during german spring offensive. second battle of somme represented bef response german attack. in turn began hundred days offensive, led eventual defeat of german army on western front, after first , third armies broke through hindenburg line @ battle of canal du nord. led final battle of war in november 1918, battle of sambre first, third , fourth armies , capture of mons, 11 november 1918, first army.