Principal battles of theBritish Expeditionary Force 1914Battle of MonsBattle of Le CateauFirst Battle of the MarneFirst Battle of the AisneBattle of La BasséeFirst Battle of Ypres1915Battle of Neuve ChapelleSecond Battle of YpresBattle of FestubertBattle of Loos1916Battle of the SommeAttack at Fromelles1917Battle of ArrasBattle of the MessinesThird Battle of YpresFirst Battle of Cambrai1918First Battle of the Somme (1918)Battle of the LysSecond Battle of the AisneSecond battle of the MarneHundred Days' OffensiveBattle of AmiensSecond Battle of the Somme (1918)Battle of ÉpehySecond Battle of CambraiBattle of Sambre The British Expeditionary Force (BEF) was the formation of the British Army on the Western Front during the First World War. In its original form it comprised six divisions, sent by Britain to France in 1914 to aid in resisting the German invasion.

Planning for a British Expeditionary Force began with the 1906–1912 Haldane Reforms of the British Army carried out by the Secretary of State for War Richard Haldane following the Second Boer War (1899–1902).

The designation "British Expeditionary Force" remained the official name of the British armies in France and Flanders throughout the First World War; but in general usage the term often refers only to the forces present in France during 1914, up to the end of the First Battle of Ypres (22 November) or to 26 December, when the BEF was divided into the First and Second Armies. (A Third, Fourth and Fifth were created later in the war). During that year the BEF helped stop the German advance, but by the year's end after the battles of Mons, Le Cateau, First Aisne and First Ypres the then BEF had been almost exhausted.

Emperor Wilhelm II of Germany, who was famously dismissive of the BEF, was widely said in Britain to have issued an order on 19 August 1914 to "exterminate ... the treacherous English and walk over General French's contemptible little army". Hence, in later years, the survivors of the 1914 army dubbed themselves "The Old Contemptibles". No evidence of any such order being issued by the Kaiser has ever been found.

Formation

Under the terms of the Entente Cordiale the United Kingdom had a diplomatic "understanding" with France to counter military aggression from the German Empire in the European continent. Detailed plans had been made for the British Army in the event of war breaking out between those two countries to dispatch an Expeditionary Force to France which consisted of six infantry divisions and five cavalry brigades under the command of General Sir John French to repel any German attack in the West. The BEF was arranged into I Corps, under the command of General Sir Douglas Haig, and II Corps, under the command of General Sir James Grierson, which embarked for France on 15 August 1914. The Expeditionary Force was given the prefix "British" on the arrival of Expeditionary Force A from the Indian Army.

In October 1914, 7th Division arrived in France, forming the basis of III Corps and the cavalry had grown to form the Cavalry Corps of three divisions. By December 1914, the BEF had expanded to such an extent that the First Army and the Second Army were formed.

By the end of 1914, after the battles of Mons, Le Cateau, the Aisne and Ypres, the old regular British Army had suffered massive casualties and lost most of its fighting strength but had managed to help stop the German advance.

Command structure

The force was commanded by Field Marshal Sir John French until December 1915, when he was replaced by General Sir Douglas Haig. The BEF's Chief of Staff on mobilisation was General Archibald Murray.Oxford Dictionary of National Biography J. E. Edmonds, 2004 He was replaced in January 1915 by General William Robertson. Lieutenant-General Launcelot Kiggell then served as Chief of Staff from December 1915 to January 1917 when he was succeeded by Lieutenant-General Herbert Lawrence. The first two Corps were commanded by Haig (I Corps) and Horace Smith-Dorrien (II Corps).

Kitchener's New Army

As the Regular Army's strength declined, the numbers were made up, first by the Territorial Force, then by volunteers from Lord Kitchener's New Army. By the end of August 1914, he had raised six new divisions and by March 1915, the number of divisions had increased to 29. The Territorial Force was also expanded, raising second and third-line battalions and forming eight new divisions, which supplemented its peacetime strength of 14 divisions. The Third Army was formed in July 1915 and with the influx of troops from Kitchener's volunteers and further reorganisation, the Fourth Army and the Reserve Army, became the Fifth Army in 1916.

Expansion

First Army

The BEF grew from six divisions of the British regular army and reserves in 1914, to encompass the British Empire's war effort on the Western front in 1918 and some of its allies. Over the course of the war 5,399,563 men served with the BEF, the peak strength being 2,046,901 men. The First Army was formed on 26 December 1914. Its first commander was Douglas Haig promoted from command of the I Corps. When Haig took over command of the BEF in 1915, the new commander was General Henry Horne. First Army remained in France until the end of the war.

Second Army The Second Army was formed at the same time as the First Army on 26 December 1914. The first commander was Smith–Dorrien promoted from command of the II Corps. In May 1915, Smith–Dorrien was sacked and replaced by General Herbert Plumer. Second Army served in France notably in the Ypres Salient, and later served in Italy between November 1917 and March 1918, then returned to France.

Third Army The Third Army was formed in July 1915, the first commander being General Edmund Allenby promoted after commanding the Cavalry Corps and the V Corps. He was replaced after the battle of Arras in May 1917, by General Julian Byng.

Fourth Army The Fourth Army was formed in February 1916, under the command of General Henry Rawlinson. Confusingly, when the Second Army was sent to Italy late in 1917, the Fourth Army was renumbered the Second Army whilst Rawlinson commanded the Ypres Salient. After Plumer's return from Italy Rawlinson spent a period as British Permanent Military Representative at the Supreme War Council at Versailles, but at the start of April he took over the remnants of Hubert Gough's Fifth Army after its recent defeat. It was renamed the Fourth Army.

Reserve/Fifth Army

The Reserve Army was formed in May 1916, under command of General Hubert Gough. Beginning as the Reserve Corps, it was expanded and renamed the Reserve Army and became the Fifth Army in October 1916. Fifth Army suffered heavy losses during the German spring offensive in March 1918. It was reformed again in May 1918 under the command of General William Birdwood.

Area of operations

1914

The British Army first engaged the Imperial German Army in the Battle of Mons on 23 August 1914, which was part of the greater Battle of the Frontiers. The mass rifle fire of the professional British soldiers inflicted heavy casualties on the Germans who attacked en masse over terrain devoid of cover.General French, First dispatch third supplement to the London Gazette 8 September 1914 The British held up the German advance until the evening when they began retiring to a second defensive line in the retreat from Mons during which they were engaged in the Battle of Le Cateau. Following the battle at Le Cateau, the BEF retreated unmolested by the Germans for a further five days, eventually retreating a full 400 km in thirteen days.

The Allied retreat finally ended at the River Marne, where Entente forces 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 a major turning point of the war: it denied the Germans an early victory.General French Second dispatch, second supplement to London Gazette 16 October 1914 From 13 September the First Battle of the Aisne took place, with both sides starting to dig trenches. Then for three weeks following the development of trench warfare, each side gave up frontal assaults and began trying to encircle each other's flank. This period became known as the Race to the Sea: the Germans aimed to turn the Allied left flank, and the Allies sought to turn the German right flank.General French, Third despatch second supplement to London Gazette 16 October 1914

By the end of First Battle of Ypres both sides started to dig in and trench warfare replaced the manoeuvre warfare that had featured during the Race to the Sea. The continuous trench lines of the Western Front now stretched from the North Sea to the Swiss frontier. 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 in 1914, to over in 1918, in the area commonly known as Flanders.

1915 From the end of 1914, and in 1915, BEF attacks centred around the Ypres Salient. Then in September 1915, six divisions took part in the Battle of Loos – notable for the first use of poison gas by the British.

1916 In 1916 the BEF had moved into the Picardy region of France. The Battle of the Somme dominated British military activity for the year. Allied forces attempted to break through the German lines along a front north and south of the River Somme in northern France. On the first day on the Somme the BEF suffered 57,000 casualties. After the war a final tally counted 419,654 British and 204,253 French killed, wounded, or taken prisoner; of the 623,907 total casualties, 146,431 were either killed or missing.

1917 In 1917 the BEF's attacks moved along the front, they operated in the Pas-de-Calais during the Battle of Arras. They then concentrated in Belgium for the Battle of Messines and the Battle of Passchendale, and ended the year back in the Pas-de-Calais for the Battle of Cambrai.

1918 In the spring of 1918 the BEF came under attack both in Flanders and on the Somme during the German spring offensive. The Second Battle of the Somme represented the BEF response to the German attack. This in turn began the Hundred Days Offensive, which led to the eventual defeat of the German Army on the western front, after the First and Third armies broke through the Hindenburg Line at the Battle of the Canal du Nord. This led to the final battle of the war in November 1918, the Battle of the Sambre by the First, Third and Fourth Armies and to the capture of Mons, 11 November 1918, by the First Army.

Empire, Indian and Portuguese contribution The British Empire responded to the call for troops for the Western Front and major formations from the dominions included Canadian Army, Australian Army, New Zealand Army and the South African Army, all served in France. The BEF also integrated the British Indian Army and most of the Portuguese Army troops who fought on the Western Front.

Indian Expeditionary Force A