Degree in Law, University Kiel, 1963. Habilitation Public Law and Law of Europe, University Münster, 1969.
Research assistant Universities Kiel and Münster, 1964-1970. Professor law University Bochum, 1970-1981. Professor law, director Institute Local Government Law University Münster, 1981.
Rector Westfälische Wilhelms University, Münster, 1986-1990. President Conference of German Rectors, since 1990. Dean and member senior University Bochum, 1974-1975.
Call to chair public law, University St. Gallen, 1980. Member subcommittee Parliament of the State of Northrhine-Westfalia, European Integration, 1988. Member Columbus Projmect of Conference of European Rectors, advisory board University Relations Europe and Latin American.
Member Association German Teachers Public Law (board member 1984-1986), International Institute Administrative Law (member German section), Association for Local Government Law and Politics, Association Counties in Northrhine-Westfalia (advisory council).
Married Bernhild Messemer. Children: Christian, Sabine, Thomas.