Professor Mohamed Mansour is one of the world-wide most renowned scientists in control engineering. During his long career his main interests have been primarily connected with stability problems of control systems, and with questions of digital control. Especially in the field of control stability he found new solutions and criteria on an analytical basis, and significantly extended known theories to more general and non-classical cases. The Retrospective which follows is a summary of his thoughts in this field. Emphasis of his work has been more on a theoretical basis, but Professor Mansour considered also cases of practical relevancy.
 

Mohamed Mansour was born in Damietta, Egypt in 1928. After receiving his BSc and MSc degrees in electrical engineering from the University of Alexandria, he studied electrical engineering at the ETH in Zurich, Switzerland, obtaining the DrScTechn degree in 1965. After a short appointments at Queen's University in Canada, he returned to the ETH in 1968 where he subsequently became Professor and Head of the Institute for Automatic Control until his recent retirement. Between 1974 and 1995, he also had visiting appointments at the IBM Research Lab (San Jose, California), University of Florida, University of Illinois, University of California (Berkeley), Australian National University, and Tokyo Institute of Technology.
 

He was President of the Swiss Society for Automatic Control (1979-1985); Member of the Council and Treasurer of the International Federation of Automatic Control (1981-1993); and has been involved in the organization and chairing of various conferences and symposia for IFAC. He has also been Chairman of the committee for Engineering Sciences of the Third World Academy of Sciences, and its representative to the United Nations (1991-present). Among his awards and recognitions are the Silver Medal of the ETH (1965), Fellow of the IEEE (1985), the IFAC Outstanding Service Award (1990), and the Guillemin-Cauer Award of the IEEE CAS Society (1992).
 

Professor Mansour's hobbies are languages, philosophy (and religions), table tennis, and tennis.
 

(Prepared by Friedrich Pfeiffer and Arthur Leissa)