Short answers, pulled from the story.
R. J. Mitchell, chief designer at Supermarine Aviation Works, designed the Spitfire. He worked on the design until his death from cancer in 1937, after which his colleague Joseph Smith took over and guided the aircraft's development through all subsequent variants.
The Spitfire prototype, K5054, made its first flight on the 5th of March 1936 from Eastleigh Aerodrome. The flight lasted eight minutes and was piloted by Captain Joseph "Mutt" Summers, chief test pilot for Vickers.
A total of 20,351 Spitfires of all variants were built, including two-seat trainers. Production ran from 1938 until the last aircraft left the production line on the 20th of February 1948.
During the Battle of Britain (July-October 1940), Spitfires were tasked with countering Luftwaffe escort fighters, mainly the Messerschmitt Bf 109E, while Hurricane squadrons targeted the bombers. Spitfire units had a lower attrition rate and a higher victory-to-loss ratio than Hurricane units throughout the battle.
The elliptical wing, designed by aerodynamicist Beverley Shenstone, solved two competing requirements: the wing needed to be thin to reduce drag but thick enough at the root to house the retractable undercarriage and eight guns. An elliptical planform produces the lowest amount of induced drag for an untwisted wing and allowed the thinnest possible cross-section with sufficient internal space.
Approximately 240 Spitfires are preserved as of 2025, including around 70 that are airworthy. The oldest surviving example is a Mark 1, serial number K9942, first flown in April 1939 and now preserved at the Royal Air Force Museum Cosford in Shropshire.