In 1882, the Douglas brothers, William and Edward, formed the Douglas Engineering Company in Kingswood, Bristol to carry out foundry work.
The horizontally opposed twin cylinder (flat twin) engine had originally been designed by German engineer, Karl Benz.
The flat twin engine for which the Douglas company became well known, was designed by Joseph Barter, the founder of Light Motors Ltd.
Barter had produced a single-cylinder motorcycle between 1902 and 1904, and then the 200cc flat twin called the Fairy, using components manufactured at the Douglas foundry.
Light Motors Ltd. failed in 1907 and was taken over by the Douglas brothers. Barter joined Douglas to continue with motorcycle design.
In 1907, the first Douglas motorcycle appeared. It featured a 350cc version of the flat twin and single speed belt drive. One of the cylinders faced forwards whilst the opposing cylinder faced the rear of the motorcycle. Initial sales were not too impressive.
In 1910, a two speed gearbox had been introduced, and this improved sales figures.
In 1911, two of three Douglas entries finished in the Isle of Man TT Races.
William Douglas rode one of the machines into seventh place in just over four hours.
G.L. Fletcher came twelfth.
1912 was more successful for Douglas in the Isle of Man Junior TT Race.
Harry Bashall came first at an average speed of 39.65mph.
In second place was Edward Kickham who achieved the fastest lap at 41.76mph.
J. Stewart came in fourth position and Jack Haslam came eighth.
In 1913, Douglas entered thirteen machines in the Isle of Man Junior TT Race.
Seven of these machines finished the race, the best position being W. Newsome who came in second place.
In 1914, the best that Douglas could manage in the Junior TT Race was seventh place ridden by E.E. Elwell.
Douglas continued to enter the TT Races with some reasonable results.
During World War I, Douglas manufactured many motorcycles for military use.
By 1920, the range included overhead valve machines 500cc and 733cc, as well as side valve machines of 350cc and 595cc.
The 350cc side valve machines were reconditioned military WD models.
Also in the 1920s, the RA models were introduced for racing. They featured disc brakes developed at the Research Association.
In 1923, production RA models were introduced in 346cc and 596cc versions.
The 348cc side valve EW models followed shortly after.
TT success returned to Douglas in 1923 when Tom Sheard won the Senior TT. Also in 1923, Douglas won the first ever Isle of Man Sidecar Race with the famous Douglas banking sidecar ridden by Freddie Dixon and T.W. Denny.
A Douglas ridden by A.H. Alexander came third in the Junior TT that year.
Later in 1923 Jim Whalley won the French Grand Prix on a Douglas.
Percy Flook won the gruelling Durban-Johannesburg Race in 1923 riding a 2.75 hp machine. He achieved an average speed of 43 mph over 430 miles.
In 1927, both 350cc and 600cc versions of the EW were available and in 1928 a 350cc ohv Sports model based on the EW was introduced.
In 1929 came the S5 and S6 models, developed by the well known motorcycle racer and tuner, Freddie Dixon.
Another Dixon design, the 350cc A31 followed in 1930.
In 1931, the overhead valve K32 and M32 models were introduced.
In 1932, after twenty five years of motorcycle production, Douglas became a limited company known as Douglas Motors Ltd.
They were to continue manufacturing motorcycles for a further twenty five years.
In 1934, the Blue Chief and the Endeavour, a 494cc flat twin shaft drive model were introduced.
By 1935, the company was struggling financially and was taken over by by the British Aircraft Company (BAC) who then formed a new company, Aero Engines Ltd.
The company continued to manufacture side valve 350cc, 500cc and 600cc models up to the breakout of World War II.
Motorcycle production continued into World War II and for the war effort, the company manufactured a variety of products including generators, aircraft components and industrial engines.
In 1945, the T35 was introduced featuring a 350cc flat twin engine with chain drive.
In 1946, the company became known as Douglas (Kingswood) Ltd.
In 1948, not long after the war, Douglas was facing financial difficulty again and production was restricted to the 350cc flat twin models.
In the early 1950s, Douglas became the UK importer and constructor of the Piaggio Vespa scooters.
In 1955, the 350cc Douglas Dragonfly was introduced. This was the last motorcycle to be produced by Douglas.
The Dragonfly featured a 348cc flat twin engine, four speed gearbox and chain drive.
In 1957, when Westinghouse Brake and Signal took over Douglas, production of Douglas motorcycles came to an end.
The production of the Vespa scooters at the Douglas factory also ended, however the company did continue to assemble scooters from parts imported from Italy.
Under Westinghouse, Douglas continued to sell Piaggio scooters and when Piaggio acquired the Gilera motorcycle brand in 1969, Douglas also became the UK importer for Gilera.
This continued through until 1982 when the import licence came to an end.