OTTO, Bishop of FREISING. — Celebrated historian of Frederick Barbarossa, b. between 1111 and 1115, son of Margrave Leopold III of Austria and Agnes, daughter of Henry IV, d. at Morimond in 1158. He studied in Paris around 1128. Cistercian monk at Morimond before 1138; shortly afterward Bishop of Freising. In 1145, entrusted with an embassy to Eugenius III, he had the opportunity to become acquainted with Italy and the political situation there. In 1147–48 he took part in the Second Crusade. He accompanied Barbarossa on his first descent into Italy and strove to smooth out the frictions between the Emperor and Adrian IV.
The *Gesta Friderici* offer a very detailed picture of the political events of which O. was a direct witness, and transmit lively traits of the spiritual physiognomy of several contemporary figures. Much has been debated regarding the method and historiographical value of the *Chronicon* or *Historia de duabus civitatibus*, which, though inspired by apostolic theological concepts, draws upon Orosius and other sources, and is undoubtedly the most notable product of medieval historiography.
Well-versed in philosophy, O. shows himself well informed about the dialectical controversies of the time, recalling their protagonists. In his own right, he appears to have been influenced by the school of Gilbert de la Porrée (v.). He was among the first to bring to Freising and Germany the treatises that form the *Ars* or *Logica nova*.