British Expeditionary Force ( World War II ) The British Expeditionary Force ( BEF ) was the British force in Europe from 1939 – 1940 during the Second World War . Commanded by General Lord Gort , the BEF constituted one - tenth of the defending Allied force . The British Expeditionary Force was started in 1938 in readiness for a perceived threat of war after Germany annexed Austria in March 1938 and the claims on the Sudetenland , which led to the invasion of Czechoslovakia in March 1939 . After the French and British had promised to defend Poland , the German invasion of that country began and war was declared on 3 September 1939 . The BEF was sent to France in September 1939 and deployed mainly along the Belgian — French border during the so - called Phoney War leading up to May 1940 . The BEF did not commence hostilities until the invasion of France on 10 May 1940 . After the commencement of battle , they were driven back through Belgium and north - western France , forcing their eventual evacuation from several ports along the French northern coastline in Operations Dynamo , Ariel and Cycle . The most notable evacuation was from the Dunkirk region and from this the phrase " Dunkirk Spirit " was coined . Background . There were reports and the beginnings of a move to mobilise an armed force in 1936 , when plans to expand the Territorial Army were put in place after a report was given to the House of Commons on 12 March 1936 . It was realised that the invention of the aeroplane had moved the defence of Britain from her own shores to those of the continent as Mr Duff Cooper ( the Secretary of State for War ) said in his report : " It was said in the leading article of the " Times " this morning : For more centuries than need be counted the destiny of Northern France and of the Low Countries has been held vital to the security of Britain . That situation has not been changed by modern inventions . It was Napoleon who said that Antwerp in the possession of a hostile nation was like a pistol held at the head of Great Britain . The result of new inventions is that that menace is greater than it was before , because to - day it is a double - barrelled pistol . It is not only a base for shipping and submarines , but is also a taking - off ground for aeroplanes . The invention of flying , so far from rendering us more immune , has robbed us of a great part of our immunity . The sea , as Shakespeare said — The silver sea , which serves it in the office of a wall . serves no longer in that office . More than ever we are part of the Continent of Europe ; less than ever can we rely upon any special advantage from our insular position . In that same report , conscription was also discussed as it was realised that there would not be enough time to expand the army to satisfactory levels " To - day , when there are still numbers of young active men unemployed and living on the dole , what better advice could be given to them than that they should join the Army ? There they would find the opportunity of a healthy , open - air life . " Conscription was not considered until war broke out , as volunteers were preferred , although by March 1937 there was still a shortfall of 60 , 000 men in the regular army . Recruiting had risen by 33 % from 1936 – 1937 , and in February 1938 it was 44 % higher than the previous year . The demand was still not met with only 34 , 000 accepted for enlistment with 30 % taken from the unemployment line . The Regular Army was backed up by the Territorial Army and both were expanded and equipped for more appropriate measures than had been previously anticipated . In March 1937 , the army stood at 121 , 000 at home and 89 , 000 overseas with 716 tanks of which 200 were obsolete First World War models . In a speech by Mr Hore - Belisha ( Cooper ' s successor ) on 10 March 1938 , the numbers were given as 500 , 000 ( excluding the colonies ) and recruiting was at 60 , 000 a year . Nevertheless , there were shortages of 1 , 200 officers and 22 , 000 other ranks . Talks about the formation of the BEF between British and French ministers were concluded after British ministers visited France in November 1938 . The French delegation announced that they believed a larger force than had been sent in 1914 was necessary , with the French cabinet saying that the British contingent would have been inadequate if war had broken out in September 1938 . After questions in the House of Commons on 28 November 1938 , the then Prime minister , Neville Chamberlain , said there was no commitment to send an expeditionary force to France . Sir P . Harris asked the Prime Minister whether this country is , in certain circumstances , committed to send an expeditionary force to France ; and whether , as a result of his visit to Paris , there has been any increase in such commitments ? The Prime Minister answered " The answer to both parts of the question is in the negative " — Hansard Vol 342 , 28 November 1938 . According to the 1939 Army Estimates , Britain had home forces of 230 , 000 in the Regular Army with 183 , 000 in reserve and The Territorials numbering 270 , 000 : a total of 683 , 000 Deployment . Following the German invasion of Poland on 1 September 1939 , the British Expeditionary Force was sent to the Franco - Belgian border in mid - September . The first deployment was completed by 11 October 1939 at which point 158 , 000 men had been transported to France . The Secretary of State for War , Leslie Hore - Belisha , said " 158 , 000 had been transported across the Channel within five weeks of the commencement of the present war . Convoys had averaged three each night and the BEF had been transported intact without a single casualty to any of its personnel . " He also claimed in Parliament that the BEF was " as well , if not better , equipped than any similar army " , which was false . During that summer , an amazed German military attaché in Britain watched troops on maneuvers march with gas pipes and pieces of wood to represent anti - tank rifles , and carry blue flags to represent trucks they rode in . One lieutenant stuffed his holster with paper because he had no pistol , and one soldier who joined the Royal Artillery in April did not receive his uniform until July . There were immense pressures to produce the necessary equipment , which led to a rapid increase in output . Clothing items were one example of this with items such as greatcoats and boots being produced at up to 50 times the normal peacetime rates . Twenty - five years of greatcoats were produced in six months and 18 months of army boots were turned out in one week , but shortages remained ; even after the Germans began moving west in May 1940 , only three of the 5th Battalion Green Howards had pistols , and the unit similarly lacked compasses and binoculars . By 19 October the BEF had received 25 , 000 vehicles to complete the first deployment . The majority of the troops were stationed along the Franco - Belgian border ; a reinforced division called Saar Force served with the French Third Army on the Maginot Line ( see pic . 5 below ) . Belgium and The Netherlands were neutral countries at this point and so no troops were sent to either of them . For those troops along the Maginot line the inactivity and an undue reliance on the fortifications , which it was believed would provide an unbreakable defence , led to " Tommy Rot " – as portrayed by the song " Imagine me on the Maginot Line " . Morale was high amongst the British troops but the small - scale actions of the Germans by 9 May had led many into assuming that there would not be much chance of a full scale German attack in that area . Over the next few months , troops , materials and vehicles continued to arrive in France and Belgium and by 13 March 1940 the BEF had doubled in size to 316 , 000 men . By May 1940 the BEF order of battle consisted of 10 infantry divisions in three corps ( I , II , and III ) , 1st Army Tank Brigade , the BEF Air Component RAF detachment of about 500 aircraft and the Advanced Air Striking Force ( AASF ) long - range RAF force . These forces were led by the General Headquarters ( GHQ ) which consisted of men from Headquarters Troops ( 1st Battalion Welsh Guards , 9th Battalion The West Yorkshire Regiment and the 14th Battalion The Royal Fusiliers ) , the 1st Army Tank Brigade , 1st Light Armoured Reconnaissance Brigade and HQ Royal Artillery 5th Infantry Division . This period leading up to 10 May 1940 was known as the Phoney War , as there was little combat apart from minor clashes of reconnaissance patrols . The Allied generals believed that time was on their side , and hoped to weaken Germany by blockade before going on the offensive . The plan by General Gamelin , the Commander - in - Chief of Allied Forces , to counter a German attack through Belgium , was to move his most mobile armies ( including the BEF ) forward across the border to the line of the River Dyle . This operation was known as the Dyle Plan , and it depended on the Belgians being able to stall any German invasion for several days with their border fortifications on the Albert Canal and River Meuse . Action . Hitler ' s forces began the Blitzkrieg on 10 May 1940 . The German Army Group B , led by Fedor von Bock , crossed into Belgium ; the lynchpin of the Belgian defence at Fort Eben - Emael having been captured by airborne assault early that morning . By 12 May , 35 Allied divisions , including 10 of the BEF had reached the River Dyle as planned , however forward elements of Army Group B arrived on 15 May . Although the initial German attacks were held , it was clear that the main threat was further south , where Army Group A , led by Gerd von Rundstedt , had unexpectedly emerged from the Ardennes Forest and crossed the River Meuse at Sedan , routing the French Second and Ninth Armies in the process . With Army Group B close behind , the Allies began a withdrawal towards the River Escaut on the French border . The push by Army Group A towards the coast combined with the approach of Army Group B from the Northeast left the BEF surrounded on three sides and cut off from their supply depots by 21 May ( pic . 2 below ) . The British forces attempted to stop the offensive and launched counter - attacks including at Arras on 21 May . The BEF was unable to repel the Germans and it became clear that the Channel ports were threatened . Fresh troops were rushed from England to defend Bolougne and Calais , but after hard fighting , both ports were in German hands by 26 May ( see Siege of Calais ( 1940 ) ) . Gort ordered that the BEF should withdraw to Dunkirk , the only viable port remaining , to facilitate evacuation ( pic . 3 below ) . Evacuation . The BEF sustained heavy losses during the German advance and most of the remainder , approximately 198 , 229 men along with 139 , 997 French and some Belgian troops , were evacuated from Dunkirk between 26 May and 4 June 1940 ; abandoning much of their equipment after disabling their vehicles and main weapons . The 51st ( Highland ) Infantry Division was cut - off to the south of the BEF and most of it surrendered , along with elements of the French 10th Army , at Saint - Valery - en - Caux on 12 June , after an attempted rescue called Operation Cycle had partly failed . The Royal Navy ships needed assistance after the docks , harbours and piers were bombed by the Germans . Because of shallow water along the coast , British destroyers were unable to approach the evacuation beaches and soldiers were having to wade out to the warships , with many of them waiting for hours shoulder - deep in water . On 27 May the small - craft section of the British Ministry of Shipping telephoned boat builders around the coast , asking them to collect all boats with " shallow draft " that could navigate shallow water . Some of them were taken with the owners ' permission — and with the owners insisting they would sail them — while others were requisitioned by the government with no time for the owners to be contacted . These flotillas of small boats , combined with the naval vessels , would continue until the evacuation was called off on 3 June 1940 . The German forces were unable to press home an initial capture of the Allied Forces at Dunkirk and on 31 May General Georg von Küchler assumed command of all the German forces at Dunkirk . His plan was an all - out attack across the whole front at 11 : 00 on 1 June . The French held the Germans back while the last troops were evacuated . Just before midnight on 2 June , Admiral Bertram Ramsay , the officer commanding the evacuation , received the signal " BEF evacuated " and the French began to fall back slowly . By 3 June , the Germans were two miles from Dunkirk , which meant that that night was the last for evacuation . At 10 : 20 on 4 June , the Germans hoisted the swastika over the docks . Several high – ranking German commanders , including Generals Erich von Manstein and Heinz Guderian as well as Admiral Karl Dönitz , considered the failure of the German High Command to order a timely assault on Dunkirk , and to so eliminate the British Expeditionary Force , as one of the major mistakes the Germans had made on the Western Front . The Second BEF and Operation Ariel . Once the Dunkirk evacuation had started , the attentions of Churchill and the Chiefs - of - Staff were drawn to the troops who had been cut - off to the south of the German Army Group A ' s drive to the sea . They were ; the 51st ( Highland ) Division , most of the 1st Armoured Division , and an improvised force called Beauman Division . The 52nd ( Lowland ) Infantry Division had been rushed to Cherbourg after the start of the blitzkrieg and the 1st Canadian Infantry Division were on their way . It was hoped that these forces might be sufficient to help stabilise the French defence and , if all else failed , there was talk of creating a " redoubt " or fortified foothold in the Brittany peninsula . General Alan Brooke had distinguished himself by his handling of II Corps , and was withdrawn to London on 29 May to command the new corps in the south which became known as the 2nd BEF . In addition to the forces already in France or " en route " , Brooke requested that Montgomery ' s 3rd Infantry Division , who had just returned from Dunkirk , be made ready to join his new command . The bulk of 51st ( Highland ) Division had already been lost before Brooke arrived in France on 13 June and he quickly realised that there was little hope of success for the rest of his command , which included more than 100 , 000 logistic troops who had not been trained for combat . On 14 June , Brooke persuaded Churchill that all British troops should be evacuated from France without delay . From 15 to 25 June 191 , 870 allied troops ( 144 , 171 of them British ) and a large amount of their equipment were rescued from eight major sea ports on the south west coast of France in " Operation Ariel " . The only serious setback was the bombing of the troopship " Lancastria " off St Nazaire , resulting in the deaths of about 4 , 000 of those onboard ; the exact number has never been established . Aftermath . Winston Churchill referred to the outcome as a " miracle " and the British press presented the evacuation as a " disaster turned to triumph " . The rescue of the British troops at Dunkirk provided a psychological boost to British morale and begat the phrase " Dunkirk spirit " , when used to describe the tendency of the British public to pull together in times of adversity . In the various evacuations , an estimated 384 , 000 British servicemen came home , but the BEF had suffered 11 , 000 killed ( roughly a third of those were on the " Lancastria " ) , 14 , 070 wounded had been evacuated and 41 , 030 were taken prisoner . While the British Army had lost a great deal of its equipment and vehicles in France , it still had most of its soldiers and was able to assign them to the defence of Britain . Once the threat of invasion had receded , they were transferred overseas to the Middle East and other theatres , and also provided the nucleus of the army that returned to France in 1944 . For every seven soldiers who escaped through Dunkirk , one man was left behind as a prisoner of war ( POW ) . The majority of these prisoners were sent on forced marches into Germany to towns such as Trier , the march taking as long as 20 days . Others were moved on foot to the river Scheldt and were sent by barge to the Ruhr . The prisoners were then sent by rail to POW camps in Germany . The majority ( those below the rank of corporal ) then worked in German industry and agriculture for five years . No specific campaign medal was awarded for the Battle of France ; however , any serviceman who spent 180 days in France between 3 September 1939 and 9 May 1940 , or " " a single day , or part thereof " " in France or Belgium between 10 May and 19 June 1940 , qualified for the 1939 - 1945 Star . An intelligence report by the German IV Army Corps written in the summer of 1940 in preparation for Operation Sealion said of the men of the BEF :