Caesarius. A learned monk of the Cistercian monastery of Heisterback near Bonn, born about 1170 at Cologne, died about 1240 as Prior of Heisterbach. Abbot Henry requested Caesarius to draw up an abstract of his teaching, and this resulted in the famous Dialogue magnus uisionum atque miraculorum, Libri XII, which it is no exaggeration to say was probably the most popular book in Germany of its period. More than fifty MSS. are extant, and seven printed editions are known. The latest, two volumes, was edited by Strange, Cologne, 1851; an index to this followed, Cologne, 1857.