The company was created following the purchase by Armstrong Whitworth of Siddeley-Deasy, a manufacturer of luxury motor cars that were marketed to the top echelon of society.

After the merge of companies, this focus on quality continued throughout in the production of cars, aircraft engines, gearboxes for tanks and buses, rocket and torpedo motors, and the development of railcars.

Company mergers and takeovers with Hawker Aviation and Bristol Aero Engines saw the continuation of the car production which ceased in August 1960.

Considered "an elegant car appropriate for royal use", the "Armstrong Siddeley Saloon" was used by the Prince of Wales (later King Edward VIII) during his 1930 tour of Uganda.

[note 1] A few months later Herbert Austin left to form his own business and Siddeley was appointed general manager.

This was a pioneering year for the marque, during which it first offered the Wilson preselector gearbox as an optional extra; it became standard issue on all cars from 1933.

The company's rather staid image was endorsed during the 1930s by the introduction of a range of six-cylinder cars with ohv engines, though a four-cylinder 12 hp was kept in production until 1936.

Only one of those 16 special cars is now known to exist: a 1933, Long-15 Rally Tourer which, according to the records, shared the same body as the 20 hp version (which had a slightly longer bonnet).

In 1933, the 5-litre six-cylinder Siddeley Special was announced, featuring a Hiduminium aluminium alloy engine; this model cost £950.

The week that World War II ended in Europe, Armstrong Siddeley introduced its first post-war models; these were the Lancaster four-door saloon and the Hurricane drophead coupe.

The 234 and 236 Sapphires might have looked to some of marque's loyal customers like a radical departure from the traditional Armstrong Siddeley appearance.

If the "baby Sapphire" heralded the beginning of the end for Armstrong Siddeley, it was because Jaguar had launched the unitary-construction 2.4 saloon in 1955, which was quicker, significantly cheaper, and much better-looking than the 234 and 236.

Like many British cars of this era, there are active owners' clubs supporting their continued use in several countries, e.g. the UK, Australia, New Zealand, the Netherlands and Germany.

[12] Throughout the 1920s and 1930s, Armstrong Siddeley produced a range of low- and mid-power aircraft radial engines, all named after big cats.

The company started work on their first gas turbine engine in 1939, following the design pioneered at the Royal Aircraft Establishment by Alan Arnold Griffith.

Known as the "ASX" for "Armstrong Siddeley eXperimental", the original pure-turbojet design was later adapted to drive a propeller, resulting in the "ASP".

Armstrong Siddeley later took over the Sapphire design, and it went on to be one of the most successful 2nd generation jet engines, competing with the better-known Rolls-Royce Avon.

Production ended in 1962 when Petters introduced a replacement range of lightweight small high-speed air-cooled diesel engines.

[15] In April 1958 the company obtained a licence to build the Maybach MD series high-speed diesel engines.