1917 Rotax (Motor Accessories) Ltd was formed by the brothers Eugen and Hermann Aron, with a nominal share capital of £175,000 to carry on business as a manufacturer of, and dealer in, all types of motor goods, including batteries and other electrical items. In 1917, Rotax acquired the business of H. T. Saunders and Co, Birmingham.

1920 Leitner dynamo for motor cars.

1920 October. Exhibited at the Commercial Motor Exhibition at Olympia with electrical lighting equipment for commercial vehicles.

1921 Over one-third of the issued capital of Rotax was acquired by Kynoch. In the same year Rotax amalgamated with Newton Electrical Works, Taunton, a company in which the Aron brothers already had an interest. Lucas's records show that at about this time it was meeting keen competition from Rotax in the supply of electrical equipment for cars. Nobel Industries Ltd, through Kynoch Ltd, held a substantial interest in the re-formed Rotax (Motor Accessories) Ltd, and Sir Harry McGowan (later Lord McGowan) joined the Board.

1923 Sir Harry McGowan is understood to have offered the Rotax business to Lucas. There is evidence that in 1923 Lucas and Rotax established some sort of working arrangement.

1925 The Arons suggested that Lucas and Rotax should jointly take over C. A. Vandervell and Co.

1926 An offer to C. A. Vandervell was made by Sir Harry McGowan on behalf of Lucas. The offer was accepted for a consideration of £321,745 in cash. Lucas took the view that joint management of C. A. Vandervell and Co by Lucas and Rotax would not be successful and it decided to take over Rotax also. The consideration of £707,217 for the purchase of Rotax was satisfied partly in cash but for the most part by the issue of Lucas £1 Ordinary shares. Lucas decided to concentrate manufacture of equipment for the heavier types of vehicles in C. A. Vandervell and Co and to develop Rotax for the manufacture of equipment for aircraft.

1937 British Industries Fair Advert for Electrical Equipment for Modern Aircraft. Also Electrical Tools for Industrial and Garage Equipment: Drills, Polishers, Valve Refacers, Sanders and Grinders, Aircraft Electrical Equipment, Rotary Converters, Car Equipment, etc. (Engineering/Metals/Quarry, Roads and Mining/Transport Section - Stand No. Cb.601)

1937 Lighting and starting equipment, magnetos and radio equipment. "Rotax" Aviation Equipment.

1939 Production devoted to components for the RAF and other aviation fields.

Rotax Ltd is now concerned principally with the production of equipment for aircraft.

Post-war, business declined by 90 per cent and the firm was acquired by Lucas. In 1978 One of the two factories at Hemel Hempstead was closed.