Marcel Roethlisberger or Röthlisberger (1929 – ) Swiss art historian and retired professor from the University of Geneva.
He married the art historian Biancamaria Bianco in 1962 and was visiting professor to many universities and held positions at various art institutions such as the Courtauld Institute, the National Gallery of Art (in D.C.), and the J. Paul Getty Museum.
Source: Wikipedia