The most potent element of the air defences during the Battle of Britain was provided by the excellent fighter aircraft which were the backbone of Fighter Command, the Hurricane and the Spitfire.

A product of the timely revolutionary scientific and technical advances being made in the 1930s, this new generation of all-metal monoplane fighters was developed in time to have a decisive impact in the skies over southern England in 1940. In a quantum leap, the aircraft with which the Royal Air Force was equipped jumped from the slow, obsolescent, open-cockpit biplanes with top speeds of no more than 250 mph to the sleek, stressed-skin monoplanes which could go 100 miles-an-hour faster and had much superior armament and all-round performance.

The Hawker Hurricane and Vickers Supermarine Spitfire were among the best fighter aircraft in the world in 1940. Although aerodynamically advanced for its time, the Hurricane was rugged, sturdy and workmanlike in appearance. The Spitfire, in contrast, was slender, graceful and one of the most beautiful aircraft ever built. Both were powered by a Rolls Royce Merlin engine and armed with eight wing-mounted .303-inch Browning machine guns. The Spitfire had a top speed of approximately 360 mph, the Hurricane about 30-40 mph less. In battle, the Hurricane was inferior in most performance aspects to the German fighter the Messerschmitt 109, which was faster at all altitudes and could out-climb and out-dive the Hurricane with ease. Importantly in terms of air fighting, however, the Hurricane had the upper hand in low-altitude manoeuvrability and turning circle at all altitudes. So, provided the Me109 did not join combat with an altitude advantage, the Hurricane was its match. The Hurricane's sturdiness made it an excellent gun platform and allowed it to withstand high levels of battle damage.

A superbly-designed fighting machine, the Spitfire had magnificent qualities of manoeuvrability and acceleration. It was the equal of the Me109, with each machine possessing some characteristics superior to its opponent, though the Me109 was perhaps better at altitudes above 20,000 feet. Improvements just before the beginning of the Battle in the types of propellors and the quality of aviation fuel used enhanced the performances of both the Hurricane and Spitfire, but brought increased rates of speed, climb and manoevrability and an appreciably better maximum ceiling particularly for the latter.

The Spitfire has became the symbol of first defiance and then victory to the British people in 1940. However, Spitfire development and production had always lagged behind that of the Hurricane and, during the Battle, Hurricanes outnumbered Spitfires by approximately two to one. 1,715 Hurricanes flew with Fighter Command in this period, a total far greater than all other British fighter aircraft combined.