Petrus Schaesberg earned, in 2004, his Ph.D. (summa cum laude) at Munich's Institute of Art History, Ludwig Maximilian University.
At the time of his death, Schaesberg was an adjunct professor in the Art History department at Columbia University.
Schaesberg's book Das Aufgehobene Bild published in 2007 by Wilhelm Fink Verlag, explored collage as a mode of painting — from Pablo Picasso to Richard Prince.
81–94 (with Rainer Crone) and with essays by Germano Celant, Jim Dine, Jeremy Gilbert-Rolfe, Judith Goldman, Dave Hickey, Linda Norden, Lane Relyea, Scott Rothkopf and David Shapiro Ed.
Heads (after Picasso)" (English/German, Galerie Ropac, Paris/Salzburg, 1997 (with Rainer Crone) (with an essay by Robert Rosenblum) "Juan Usle.
Ojo Roto" (English, Spanish and Catalan) Museu d'Art Contemporani, Barcelona, 1996 (with Rainer Crone) with ICCARUS