Born 1947 in Osnabrück. Study of art history, history and archaeology in Münster, Bonn, Munich, Vienna. Doctorate Bonn (1977), Bibliotheca Hertziana (1978-1988), Senior Fellow at the Center for Advanced Studies in the Visual Arts National Gallery Washington/DC (1984), german Habilitation Univ. Augsburg (1991), Professor of Art History Univ. Tübingen (1994-1999), Director and Scientific Member at the Bibliotheca Hertziana - Max Planck Institute for Art History (since 1999).