Doctor Phil., University Cologne, 1957. Postgraduate, University London and Oxford, 1960. Doctor habilitatus, University Cologne, 1968.
From assistant professor, curator to head curator, associate professor University Cologne, Germany, 1956-1975. Professor University Michigan, Ann Arbor, 1975-1989, chair department classical studies, 1985-1994, hockey club Youtie professor papyrology, 1989-1995, hockey club Youtie Distinguished University professor papyrology, 1995-2000. Director project Publication of the Petrapapyri American Center Oriental Research National Endowment of the Humanities, since 1995.
Fellow British Academy (correspondent). Member American Philosophical Society, American Academy Arts and Sciences, American Philological Association (vice president 1989-1992, 94, president 1993), American Society Papyrologists (vice president 1978-1980, president 1981-1985), International Association Papyrologists (international committee), Center for Hellenic Studies (senior fellow 1985-1990), German Archeological Institute (correspondent member, president since 1995), Beirat, Institut für Neutestamentliche Textforschung (Münster), Nordrhein-Westfälische Akademie der Wissenstr (correspondent).
Married Margarete Ursula Christine Bolder, August 8, 1955. Children: Klaus, Margarete, Heinrich, Marcus.