British Expeditionary Force (World War I) - Area of Operations

Area of Operations

The British Army first engaged the German Army in the Battle of Mons in August 1914, which was part of the greater Battle of the Frontiers. The massed rifle fire of the professional British soldiers inflicted heavy casualties on the Germans who attacked en masse over terrain devoid of cover. The British held up the German advance until the evening when, they began retiring to a second defensive line in the retreat from Mons and the Battle of Le Cateau. The British victory at Le Cateau had achieved its objective, and enabled the BEF to retreat unmolested by the Germans for a further five days.

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 10 September 1914. This battle would prove to be the major turning point of the war by denying the Germans an early victory. From the 13 September the First Battle of the Aisne took place with both sides starting to dig trenches and then for a three week period following the development of trench warfare, both sides gave up frontal assaults and began trying to encircle each other's flank. This period is called the Race to the Sea as the Germans aimed to turn the Allied left flank, and the Allies sought to turn the German right flank.

By the end of First Battle of Ypres, both sides started to dig in and Trench Warfare took over from the manoeuvre warfare that had taken place during the Race to the Sea. The continuous trench lines of the Western Front now stretched 400 miles (640 km) from the North sea to the Alps. The British Army held a small portion of this 400 mile front from just north of the pre war Belgium border to the River Somme in France, varying in length from 20 miles (32 km) in 1914, to over 120 miles (190 km) in 1918, in the area commonly known as Flanders.