This article attempts to theme et the demand for a modern biographical guide to the abbots of the Cistercian monastery at Mogiła in the Middle Ages. It is intended to replace K. Hoszowski’s "A Picture of the Lives and Outstanding Work of the Abbots of Mogiła" published in 1867. Today’s data base enables us to identify and correct various errors in Hoszowski’s work as well as introduce a lot of new information that was unknown to him.