Dunkirk: The History Behind the Major Motion Picture. Joshua Levine

he saw his first dead bodies. The first pair upset Irwin – but the second pair made him vomit, and appeared in his dreams for years afterwards. The difference was not in the manner of their deaths or even the severity of their wounds. It was in the second pair’s ‘indecent attitude’. Naked, demeaned, bloated and distorted, they embodied something worse than death.

      That evening, his battalion was under attack again. Overwhelmed, a young private began crying. Irwin took the boy aside, intending to lead him away. But the private, rigid with misery, refused to move. The only thing to do, decided Irwin, was to knock him out. He ordered a sergeant to take a swing at the private’s chin – but the sergeant missed, cracking his knuckles on a wall. The private suddenly came to life and ran, but was chased down by Irwin who tackled him, and punched him in the face. The boy was now unconscious.

      Irwin slung the private over his shoulder and carried him down to a nearby cellar. It was dark inside, and Irwin shouted for somebody to bring him a light. In the relative quiet, Irwin heard surprised voices, a man’s and a woman’s, and his eyes slowly focused on a soldier in the corner of the cellar having sex with a Belgian barmaid. Who could blame them, wondered Irwin. With death so close, they were grabbing hold of life.

      Irwin was among hundreds of thousands of officers and men of the British Expeditionary Force retreating through Belgium towards the coast. They had sailed to France following the declaration of war on Germany on 3 September 1939. After months of ‘phoney war’, the German Blitzkrieg in the west had been launched on the morning of 10 May, and the bulk of the British forces was hurried into Belgium to assume prearranged positions along the River Dyle. There they formed the Allies’ left flank, alongside the French and Belgian armies, facing Hitler’s Army Group B. Further to the south, the Allies’ right flank was protected by the mighty Maginot line, a series of heavily defended fortresses, blockhouses and bunkers along the French border with Germany.

      For a few short days in May 1940, the Allies and the Germans, broadly equal in military terms, seemed destined to act out another war of trenches and attrition. If experience could be trusted, the Germans would soon be hurling themselves at heavily defended Allied lines.

      But the Allied commanders were instead offered a sharp lesson in modern warfare. Between the strongly held Allied flanks was the Ardennes forest, theoretically impregnable, and weakly defended by the French; only four light cavalry divisions and ten reserve divisions protected a hundred-mile front. And the Germans had a plan to exploit this front.

      First formulated by Lieutenant General Erich Manstein, the plan had been through seven drafts by May 1940. It involved an initial attack on Holland and northern Belgium, drawing the Allies into a trap. For at the same time, the main German attack would come further south at the very weakest point of the Ardennes front. Led by Panzer tank divisions, it would begin by crossing the River Meuse, pushing through the area around Sedan and surging north-west for the coast, splitting the French armies in two and joining up with the northern attack to encircle the British Expeditionary Force.

      The Manstein Plan was extremely risky; breaking through a wooded area was a huge logistical challenge, and the Panzer tank was a largely untested weapon. The plan’s success depended on unprecedented speed and intensive air support, but, above all, it depended on surprise. If the French learned of it in advance, it would surely fail. In January 1940, however, the Belgians had captured a copy of the previous German plan – to launch the main assault in Holland and Belgium. This was a straightforward repeat of Germany’s First World War strategy – and the Allies had no reason to believe that the Germans were now considering an alternative.

      The level of risk involved in the Manstein Plan was so great, the break from traditional practice so complete, that most German generals refused to countenance it. It gained, however, an influential supporter in General Franz Halder, Chief of Staff of Army High Command. And, crucially, it had the support of the man whose opinion ultimately mattered in Nazi Germany – Adolf Hitler. The attack was ordered to go ahead.

      In the event, the French were taken by complete surprise. Armoured forces, spearheaded by Lieutenant General Heinz Guderian’s Panzer Corps and devastatingly supported by the Luftwaffe, plunged through enemy lines, tearing a massive hole in French defences. German tanks began to race through France unchallenged. This is why, just days after taking up their positions in Belgium, British soldiers – clearly able to hold their own against the Germans – were being ordered backwards. There must, they thought, be a localised reason. Had the Germans broken through in a nearby sector? Or was their particular battalion being sent to the rear for some misdemeanour?

      At first, British units retreated in stages, from one defendable line to another. Sometimes an entire division was pulled out, free to plug a distant gap. As the retreat gathered pace, confusion increased, and rumours began to circulate. One of these rumours proved true – an almighty breakthrough to the south was threatening to outflank the British army. But for most of the retreat there was no suggestion of evacuation, nor mention of the now legendary name Dunkirk.

      All sorts of soldiers found themselves on the move, from elite guardsmen to untrained labour troops. Some went on foot, marching in battalion strength or stumbling alone. Others travelled in trucks, on horses, tractors and bicycles. One intrepid group was observed riding dairy cattle. Under fire and lacking supplies, the men of the British army were in every kind of physical and mental state.

      One man, Walter Osborn of the Royal Sussex Regiment, was in a particularly difficult situation. Having sent the Prime Minister, Winston Churchill, an anonymous letter asking for ‘some leave for the lads’, he had been sentenced to forty-two days’ detention for using ‘language prejudicial to good order and conduct’. He was now engaged in a fighting retreat with his comrades – but he was at a disadvantage. Whenever the fighting stopped, he was locked up in a nearby barn or cellar to continue serving his sentence. This did not seem fair. As he complained to a regimental policeman: ‘A man’s got a right to know where he stands!’

      Even more unusual was the small soldier sitting in a truck on the road to Tourcoing. In steel helmet and khaki greatcoat, carrying a rifle, the soldier looked like any other. The uniform may have hung a little, but that was hardly unusual. Private soldiers weren’t expected to dress like Errol Flynn in The Charge of the Light Brigade. The odd thing about this soldier was her marriage to a private in the East Surrey Regiment.

      The soldier was Augusta Hersey, a twenty-one-year-old French girl. She had recently married Bill Hersey, a storeman in the 1st East Surreys. They had met in Augusta’s parents’ café when Hersey was stationed nearby, and despite neither speaking a word of the other’s language, they had fallen in love. Hersey had asked Augusta’s father for her hand by pointing at the word mariage in a French–English dictionary and repeating the phrase ‘Your daughter …’

      Hersey was fortunate to have a sentimental company commander who agreed – against any number of regulations – that Augusta could dress in army uniform and retreat with his battalion. This was how the couple found themselves, almost together, fleeing the German advance. But their retreat had no definite objective until Lord Gort, the British commander, reached the brave conclusion that the only way to save a percentage of his army was to send Anthony Irwin, Walter Osborn, and the rest of the British Expeditionary Force, towards Dunkirk, the one port still in Allied hands, from where some of them could be hurriedly transported home by ship.

      As they arrived at Dunkirk, soldiers were confronted by an unforgettable scene. Captain William Tennant, appointed Senior Naval Officer Dunkirk by the Admiralty, sailed from Dover to Dunkirk on the morning of 27 May to coordinate Operation Dynamo. He entered a town on fire, its streets littered with wreckage, every window smashed. Smoke from a burning oil refinery filled the town and its docks. There were dead and wounded men lying in the streets. As he walked on, he was confronted by an angry, snarling mob of British soldiers, rifles at the ready. He managed to defuse a difficult situation by offering the mob’s ringleader a swig from his flask.

      Another naval officer arrived in Dunkirk two days later. Approaching from the sea, he was struck by one of the most pathetic sights he had ever seen. To the east of the port were ten miles of beach, the entire length blackened by tens of thousands of men. As he drew closer,