Dunkirk, helping to save the British Expeditionary Force, a claim that German General Heinz Guderian contradicted in 1951. In 1966, Lionel Ellis, the British official historian, wrote that three panzer divisions had been diverted by the defence of Boulogne and Calais, giving the Allies time to rush troops to close a gap west of Dunkirk. In 2006, Karl-Heinz Frieser wrote that the halt order issued to the German unit commanders because of the Anglo-French attack at the Battle of Arras (21 May) had a greater effect than the siege. Hitler and the higher German commanders panicked because of their fears of flank attacks, when the real danger was of the Allies retreating to the coast before they could be cut off. Reinforcements sent from Britain to Boulogne and Calais arrived in time to forestall the Germans and hold them off when they advanced again on 22 May. Nicholson is portrayed by Richard Glover in the 2017 film Darkest Hour about Winston Churchill in 1940. In the film, Churchill orders Nicholson to hold out and delay the Germans so that the bulk of the British army can be evacuated from Dunkirk. Churchill's telegram to Nicholson features in a scene in the film. References External links British Army Officers 1939–1945 Generals of World War II 1898 births 1943 deaths Burials in Germany 16th The Queen's Lancers officers 16th/5th The Queen's Royal Lancers officers British Army personnel of World War I British World War II prisoners of war Companions of the Order of the Bath Graduates of the Royal Military College, Sandhurst Graduates of the Staff College, Camberley People educated at Winchester College People from Chelsea, London World War II prisoners of war held by Germany British Army personnel killed in World War II 1943 suicides Suicides by jumping in Germany British military personnel who committed suicide Military personnel from London Academics of the Royal Military College, Sandhurst Academics of the Staff College, Camberley British Army brigadiers of World War II