OTTO OF FREISING (1114?-1158), German bishop and chronicler, was the fifth son of Leopold III., margrave of Austria, by his wife Agnes, daughter of the emperor Henry IV. By her first husband, Frederick I. of Hohenstaufen, duke of Swabia, Agnes was the mother of the German king Conrad III., and grandmother of the emperor Frederick I. ; and Otto was thus related to the most powerful families in Germany. He studied in Paris, and became abbot of the Cistercian monastery of Morimond in Burgundy about 1136, soon afterwards being elected bishop of Freising. In 1147 he took part in the disastrous crusade of Conrad III., returning to Bavaria in 1148 or 1149. He enjoyed the favour of Conrad's successor, Frederick I.; was probably instrumental in settling the dispute over the duchy of Bavaria in 1156; was present at the famous diet at Besancon in 1157, and died at Morimond on Sept. 22, 1158.
Otto wrote a Clironicon, sometimes called De duabus civitatibus, an historical and philosophical work in eight books, which follows to some extent Augustine and Orosius. It goes down to 1146,
and from this date until 1209 has been continued by Otto, abbot of St. Blasius (d. 1223). Of the Gesta Friderici imperatoris the first two books were written by Otto, and the remaining two probably by his pupil Ragewin, or 'Rahewin. First printed by John Cuspinian at Strasbourg in 1515, Otto's writings are now issued in the Monumenta Germaniae historica, Band xx. (Hanover, 1868) ; German trans. by H. Kohl (Leipzig, 1881-86). The Gesta Friderici has been published separately with introduc tion by G. Waitz.
See J. Hashagen, Otto von Freising als Geschichtsphilosoph und Kirchenpolitiker (Leipzig, 1900) ; J. Schmidlin, Die geschichts philosophische and kirclienpolitisclie Weltanschauung Otto von Freising (Freiburg i./B., 1906) ; A. Hofmeister, "Studien fiber O. v. Freising" in Gesellschaft fiir dltere deutsche Geschichtskunde (Hanover, 1910 ; A. Potthast, Bibliotheca historica (1896).