During the Second World War, the 155th Infantry Brigade served with the 52nd Division during Operation Ariel in France in 1940 to cover the withdrawal of the British Expeditionary Force (BEF) which was being evacuated from France. The 52nd Division was itself evacuated from France on 17 June 1940, and spent many years on anti-invasion duties, training to repel an expected German invasion of Britain. From May 1942 to June 1944, the division was trained in mountain warfare yet was never used in the role. They were then trained in airlanding operations but were, again, never utilised in the role. In October 1944, they were sent to Belgium as a standard infantry division to join the 21st Army Group and were attached to First Canadian Army and fought in the Battle of the Scheldt where the 52nd Division gained an excellent reputation. The brigade was attached to 7th Armoured Division during Operation Blackcock in 1945 and ended the war by the River Elbe.