of Acton, London
1920 Company founded as Edward E. Rosen and Co
1925 Private company - Ultra Electric
1960 Name changed. Ultra split its electronics and receivers divisions into two companies - Ultra Electronics Ltd and Ultra Radio and Television Ltd.
1960 Ultra Electric sold the Ultra and Pilot Radio and Television businesses to Thorn Electrical Industries; Edward E. Rosen, chairman of Ultra Electric (Holdings) Ltd., announced the money received would be used to relieve pressure on liquid resources and also to meet the demands of expansion in the electronics field without raising additional capital.
Ultra Electronics Ltd. and Electronics Investment Management Corporation of USA agreed to a complete interchange of information on research, development, marketing and production of electronic equipment. At the same time 40 per cent of Ultra Electronics Ltd. was sold to Electronics International Capital Ltd. The chairman forecast considerable expansion of Ultra Electronics Ltd. in all electronic fields.
1960 Ultra Electronics acquired Trix Electronics Co, a subsidiary of the Trix Electrical Co - Trix Electronics would continue to manufacture and install sound amplification equipment for PA and aircraft.
1961 Manufacturing electronic engineers. Specialists in the field of communication systems, automatic data processing systems, communication control systems, aircraft and industrial control and instrumentation systems and printed circuitry. 1,500 employees. 
1962 In June, the "Sarah" radio beacon equipment developed by Ultra, and widely used throughout the world, was responsible for locating spaceman Scott Carpenter when he came down in the sea after his successful orbits of the earth.
1972 Ultra Electronic Holdings sold its mobile radio division
1992 Dowty was acquired by TI Group
1993 Ultra Electronics was one of seven companies which formed the Dowty Group Electronic Systems Division that was the subject of a management buyout.
1996 The company was floated on the London Stock Exchange
2015 Ultra Electronics Holdings Plc. Revenue £726m. Three divisions in 24 businesses:
- Aerospace and Infrastructure
- Communications and Security
- Maritime and Land
Employs 4,500 persons worldwide with 2,310 in the UK.