During the Second World War, a fighter pilot who scored five or more aerial victories was designated an ‘ace’. In the Battle of Britain, 188 RAF fighter pilots earned that distinction – 8 per cent of those who flew. About 2,300 enemy aircraft were shot down during the battle and about 39 per cent of the 2,332 RAF pilots who flew fighter aircraft had success in downing at least one enemy plane. The number of pilots who scored more than a single victory, however, comprised less than 15 per cent of those engaged. A total of 237 RAF pilots who fought in the battle attained ‘ace’ status later in the war. Three RAF pilots became ‘aces in a day’ by shooting down five enemy aircraft in 24 hours. Pilot Officer William Dudley Williams joined the RAFVR as an ‘Airman under Pilot Training’ in April 1938 and was called to full-time service at the outbreak of war. He joined No. 152 Squadron at Acklington as a pilot officer in May 1940 and during the Battle of Britain he shot down five enemy aircraft, shared in the destruction of another, and damaged two additional aircraft. He was awarded the DFC on 7 January 1941. The RAF tunic pictured here was worn by Williams during the Battle of Britain period, before his promotion to flying officer in April 1941. It was custom tailored by J. E. Carhart Ltd of Stoke-on-Trent. Williams was given temporary command of No. 121 (Eagle) Squadron in August 1942 and led this force of American fighter pilots flying for the RAF until their transition over to the US Army Air Force in September 1942. Williams later commanded No. 615 Squadron in India and retired from the RAF as Squadron Leader in 1945.