In 1907, the Rotax Motor and Cycle Company was already trading as a manufacturer of automotive electrical equipment in Gt Eastern St, London Wall, London and in 1916 they moved to Willesden Junction, London NW. The following year, Rotax (Motor Accessories) Ltd was formed by the brothers Eugen and Hermann Aron to carry on business as a manufacturer of, and dealer in, all types of motor goods, including batteries and other electrical items. 

In 1921, the Lucas company records show that at about this time it was meeting keen competition from Rotax in the supply of electrical equipment for cars. In 1923, the Rotax business may have been offered to Lucas and there is evidence that Lucas and Rotax established some sort of working arrangement. In 1926, a major share of Rotax was taken by Lucas who planned to develop Rotax for the manufacture of equipment for aircraft. 

By 1939, Rotax was advertising as a supplier of complete electrical and ignition apparatus for all types of modern military and civil aeroplanes. They offered Rotax-Eclipse starters for aero engines, and small motors were being supplied for retractable undercarriages and wing-flaps. 

From around 1939, Rotax Ltd became a wholly-owned subsidiary of Lucas and was substantially concerned with the production of equipment for aircraft. Post WWII, Rotax's business declined by 90 percent compared with its wartime activities. 

In 1959, Rotax offered linear and rotary actuators for all engine and aircraft applications such as under-carriage actuators of up to 30,000 lb. thrust. The company was now trading in Australia and Canada as Lucas-Rotax.

In 1968, Rotax took over the GEC-AEI aircraft equipment plant at Coventry and moved most of the operations to Hemel Hempstead. The following year, they acquired Vactric Control Equipment and the Special Products Group of English Electric Co. In 1970, the company's second largest factory at Willesden was closed due to lack of orders from new projects for aircraft starters.

During 1971, Rotax became part of Lucas Aerospace.