Following the outbreak of the Second World War, Nicholson was given command of the
30th Infantry Brigade, which was raised on 20 April 1940 to serve in
Norway. Nicholson's brigade left
Dover and reached Calais on 23 May 1940 to keep the Calais port open and relieve the defenders at the
Battle of Boulogne. With the German advance, that became impossible and Nicholson held Calais. The Germans advanced on the town and laid siege to it, shelling the town and drawing closer. This was just before the start of
Operation Dynamo, the evacuation of the
British Expeditionary Force (BEF) through
Dunkirk. The next day, Nicholson was told that his brigade might be evacuated back to Britain. As the large German force fought through the town the same day, Nicholson ordered a staged withdrawal from the ramparts to more easily defensible places in the city, such as the Citadel and the Gare Maritime, a train station. On the morning of 25 May, the Germans sent the mayor of Calais to Nicholson to ask him to surrender, saying that if he did not, they would bomb and shell the town until it was razed. Nicholson said: "Surrender? No, I shall not surrender. Tell the Germans that if they want Calais they will have to fight for it." On 26 May, the German barrage continued and in the afternoon, the Germans broke through, taking Nicholson and many soldiers prisoner. He was taken to a prisoner camp near
Salzburg, then later to one in
Hesse. On 4 June 1940, Churchill spoke to Parliament about Nicholson's defence: Nicholson was appointed a
Companion of the Order of the Bath for his services at Calais in 1940. ==Katyn incident==