London, England May 19, 1940

Following Britain and France’s decla­ra­tion of war on Germany on Septem­ber 3, 1939, neither of the Allies com­mitted to launching a signi­fi­cant land offen­sive against Adolf Hitler’s Ger­many as punish­ment for the invasion of its eastern neigh­bor, Poland, which was in a treaty relation­ship with the two Western powers. The most the British were pre­pared to do was deploy a 315,000‑man expedi­tion­ary force, with aircraft and artillery, to the Franco-Belgian border.

Hitler, however, was busy making prepar­a­tions to end the so-called Phony War (German, Sitzkrieg; French, le drôle de guerre), as this early and quiet phase of World War II came to be called. His war in the West began on May 10, 1940, when Wehr­macht forces invaded the Nether­lands, Bel­gium, Luxem­bourg, and France. A series of Allied counter­attacks failed to sever the armored German spear­head through Belgium’s Ardennes Forest, which quickly reached the English Chan­nel, swung north along the French Picardy and Nord-Pas-de-Calais coasts, and threat­ened to capture the Chan­nel ports and trap the Allied troops and their heavy equip­ment before they could escape to England.

On this date, May 19, 1940, British Prime Minis­ter Winston Chur­chill ordered the British Admi­ralty to ­draw up a con­tin­gency plan for a sea­borne rescue mis­sion that became known as the “Miracle of Dunkirk.” Using a “fleet” that grew to perhaps one thou­sand ves­sels, ranging from Royal Navy destroyers and other war­ships, whalers, cross-Chan­nel ferries, plea­sure steamers, to craft as small as Thames barges, yachts, and cabin crui­sers manned by unarmed civil­ian crews, Opera­tion Dynamo ini­tially tar­geted rescuing up­wards of 45,000 mem­bers of the British Expedi­tionary Force. That was about one-fifth of the men now hunkered down 6 miles south of the Bel­gium border and facing anni­hi­la­tion on Dunkirk’s hostile beaches. How­ever, Oper­a­tion Dynamo suc­ceeded in bringing some 198,229 men of the BEF along with 139,997 French and some Bel­gian troops to safety in England. (British and French units were given equal priority in the evac­u­a­tion.) Bad flying weather, Hitler’s dithering—he inex­pli­cably ordered Gen. Wilhelm Ritter von Thoma’s panzers to halt in place on May 24 before reversing himself two days later—and British Spit­fires saved the nucleus of the British Army and the germ of the Free French Forces (Forces fran­çaises libres), or FFL, from certain destruc­tion. (The RAF, flying from bases in Southern England, made over 4,822 sorties between May 26 and June 4.) The epic evac­u­a­tion of the trapped soldiers ended on June 4 for a loss of 226 vessels, most of them British (31 on June 1), and 145 planes (not including the Royal Navy’s Fleet Air Arm) out of 2,739 aircraft, 13 more than the Germans.

Seen by Hitler, his inner circle, and the German news media as a crushing British defeat (Wilhelm Keitel, head of the Wehr­macht High Com­mand, hailed the event as “the greatest mili­tary victory of all time”), Dunkirk (French, Dunkerque) became a major victory for British war­time morale. The Dunkirk Spirit stiffened national resolve and ended spec­u­la­tion over a nego­ti­ated settle­ment with Nazi Germany. Four years later the Wes­tern Allies returned to the con­tin­ent—to Nor­mandy on the French coast, over 200 miles south of Dun­kirk. On June 6, 1944—D-Day—the Allies were out­fitted with the largest assem­blage of inva­sion ships, aircraft, men, and equip­ment in history. In less than 24 hours, 176,000 troops had dis­em­barked from 4,000 trans­port ships to begin the West’s suc­cessful assault on Hitler’s “Festung Europa” (Fortress Europe).

Operation Dynamo and the Rescue of the British and French Armies at Dunkirk, France’s Northern­most Point, May 26 to June 4, 1940

Operation Dynamo: Dunkirk pocket, France, June 4, 1940

Above: The semicircular Dunkirk pocket, France, June 4, 1940, the last day of Opera­tion Dynamo. By then a second smaller pocket at Lille, held by rem­nants of three French divi­sions, had col­lapsed. Chur­chill origi­nally described the German entrap­ment of the British Expedi­tionary Force in France as “a colos­sal mili­tary dis­aster,” what with “the whole root and core and brain of the British Army” facing capture and extermi­na­tion. Following the conclu­sion of Opera­tion Dynamo, he hailed the rescue of the BEF as a “miracle of deliverance.”

Operation Dynamo: British soldier firing on incoming aircraft, Dunkirk, France, 1940 Operation Dynamo: Fishing boat picking up troops, Dunkirk, France, 1940

Left: A British soldier on a Dunkirk beach exchanges rounds with machine-gun strafing German air­craft. The Germans used their Luft­waffe as flying artil­lery (along with unloading explo­sive and tear gas bombs on the beaches) while their army shelled the beaches and marshy flat­lands from the ground. During the Battle of France (May 10 to June 22, 1940), the British Exped­i­tionary Force suffered 11,000 killed or missing, 14,070 evacu­ated wounded, and 41,030 taken prisoner. During the same period the French armed forces suffered between 55,000 and 85,000 killed, 120,000 wounded, and 12,000 missing, with at little over 1‑1/2 million soldiers captured and taken as prisoners of war to Germany, where roughly 940,000 remained until 1945. World War I hero Marshal Philippe Pétain, who assumed power in France in June 1940 in the wake of his coun­try’s mili­tary reverses, blamed Britain for the collapse of the French Army and char­ac­terized Operation Dynamo as a treacherous act of desertion.

Right: A British fishing boat picks up troops off the coast of Dun­kirk while a Stuka’s bomb explodes a few yards away. Many boats put them­selves in harm’s way multi­ple times, and at all hours of the day and night. In nine days, more than 338,000 Brit­ish, Common­wealth, French, and Belgian soldiers were rescued by around 220 war­ships and sun­dry 700 “little ships” flying British, French, Dutch, and Belgian flags. Under the code­name Oper­a­tion Ariel, close to another 192,000 Allied per­son­nel and civilians, 144,000 of them British service­men in what became known as the Second Expe­di­tionary Force, were evac­u­ated through other escape ports in Brittany and along the French Atlantic coast between June 15 and 25. Not only did the peril­ous evac­u­a­tions turn a mili­tary dis­as­ter into a story of sacri­fice and heroism that served to raise and sus­tain the morale of Britain’s war­time pop­u­lace, it allowed the British Army to recu­per­ate and rebuild itself for the task of liberating France four years later.

Operation Dynamo: British troops evacuating Dunkirk's beaches, France 1940 Operation Dynamo: Wounded French soldier, Dover, England

Left: British soldiers wade from Dunkirk’s pop­u­lar resort beach­front through ocean shallows to board waiting vessels. Many of the approx­i­mately 198,229 men of the BEF who were res­cued stood for hours shivering in shoulder-deep water, ex­hausted, fear­ful, thirsty, and hun­gry, easy targets for German air­craft bombs and shells. Despite the suc­cess of the rescue oper­a­tion, all heavy equip­ment and vehicles had to be left behind: 2,300 artil­lery pieces, 500 anti­tank guns, 600 tanks, almost 65,000 vehicles, and 20,000 motor­cycles—prac­ti­cally half of the British Army’s entire inven­tory of heavy wea­ponry. More than 75,000 tons of ammu­ni­tion and 162,000 tons of fuel were also abandoned. Hitler’s Ober­kom­mando der Wehr­macht (high command) consid­ered the British inca­pable of defending them­selves—out­gunned and out­numbered, at least for the near term, by Germany’s armed forces. So the Fuehrer directed prep­a­ra­tions be made for Unter­nehmen Seel­oewe (Oper­a­tion Sea Lion), the amphib­i­ous cross-Channel invasion of the British Isles planned for late-September 1940.

Right: A wounded French soldier being brought ashore on a stretcher at Dover, England, the main recep­tion port for evacuees. (Dover was 20 miles from the French coast.) Of the more than 100,000 French sol­diers who escaped from Dun­kirk, only about 3,000 chose to join Charles de Gaulle’s Free French army in London. (In his memoirs De Gaulle claims he could have recruited many more to his Free French army had British author­i­ties given him free rein to seek recruits among French evac­u­ees in Britain.) The rest of the rescued French sol­diers were repa­tri­ated back to Brest, Cher­bourg, and other French ports in Nor­mandy and Brit­tany, where roughly half of them were redeployed against the invading Germans.

Operation Dynamo: Rescued British troops, Dunkirk, France, 1940 Operation Dynamo: Rescued French troops, Dunkirk, France

Left: British troops evacuating to ship via a life­boat bridge. The British Minis­try of Shipping tele­phoned boat builders around the English coast, asking them to collect all boats with shal­low draft that could navi­gate the waters off Dunkirk’s beaches. Nine­teen life­boats of the Royal National Lifeboat Institution sailed to Dunkirk.

Right: French troops rescued by a British ship at Dunkirk. Between 30,000 and 40,000 French troops were cap­tured in the Dun­kirk pocket. For many French sol­diers who were repa­tri­ated to France, their escape from Dun­kirk was not a sal­va­tion, but repre­sented only a few weeks’ hiatus before being made prisoners of war by the German Army following the Franco-German armistice of June 22, 1940.

Contemporary Newsreel of Operation Dynamo, the Allied Evacuation of the Dunkirk Pocket, May 19 to June 4, 1940