Following the declaration of war on 3 September 1939, 41 Squadron spent the first several months on monotonous routine patrols in the north of England. At the end of May 1940, the squadron flew south to RAF Hornchurch to participate in the evacuation of Dunkirk. Twelve days later, they returned to RAF Catterick, claiming six Axis aircraft destroyed and one probable, but also left behind two pilots, the squadron's first pilot killed in action and their first lost as a prisoner of war. After resting for a few weeks, the squadron headed south again on 26 July 1940, to participate in the first phase of the Battle of Britain. In its two-week tour, the Squadron claimed 10 Axis aircraft destroyed, four probables and three damaged, for the loss of one pilot killed and a second wounded.