He was born in Budapest, Hungary. He obtained his bachelor's (1953) and master's (1954) degrees from MIT in electrical engineering. His doctorate (1957) was from Columbia University. His worked as Research Mathematician at the Research Institute for Advanced Study, in Baltimore, from 1958-1964, Professor at Stanford University from 1964-1971, and Graduate Research Professor, and Director, at the Center for Mathematical System Theory, University of Florida, Gainesville from 1971 to 1992. Starting in 1973, he simultaneously filled the chair for Mathematical System Theory at the Swiss Federal Institute of Technology, (ETH) Zurich.
He received the IEEE Medal of Honor (1974), the IEEE Centennial Medal (1984), the Inamori foundation's Kyoto Prize in High Technology (1985), the Steele Prize of the American Mathematical Society (1987), and the Bellman Prize (1997).
He is a member of the National Academy of Sciences (USA), the National Academy of Engineering (USA), and the American Academy of Arts and Sciences (USA). He is a foreign member of the Hungarian, French, and Russian Academies of Science. He has many honorary doctorates.
He is married to Constantina nee Stavrou. They have two children, Andrew and Elisabeth.