A photograph taken in 1944 shows the deck of a ship arriving at a British port crowded with orderly rows of men from the West Indies who have joined the Royal Air Force (RAF). The RAF played a key role in World War Two, the first time that aerial combat had been used extensively in war, and it required a huge force of skilled men to support the bombers and fighters. The RAF had a personnel strength of 1,185,833 men on 1 July 1944 compared to 175,692 at the outbreak of war in September 1939.