Otto is best known for two major historical works:
Chronica de duabus civitatibus The first is his work Chronica sive Historia de duabus civitatibus (Chronicle or History of the Two Cities), an eight-book historical and philosophical treatise that to some extent follows the intellectual framework laid down by
Augustine of Hippo and
Paul Orosius. Written during the German Civil War (1143–1145), it draws a parallel between
Jerusalem and
Babel, the Heavenly City and the Earthly City, while also containing a wealth of valuable information about the history of his era. Esteemed highly by his contemporaries, this chronicle covers events up to the year 1146; from that point onward to 1209, it was continued by
Saint Blasius of Blaubeuren Abbey in the Black Forest (d. 1223). In the Chronica, Otto recounts his meeting with Bishop
Hugh of Jabala, who told him of a
Nestorian Christian king in the East called
Prester John. It was hoped that this monarch would bring relief to the Crusader states, and this marks the first documented reference to Prester John. The text elaborates on an era of harmony between imperial and ecclesiastical authority, tracing its origins to the Christianization of Rome. Rome is portrayed as the fourth and final world empire, after which power passed to the Greeks (the
Byzantines), then to the Franks (
Francia), and later to the Germans (
East Francia). He also notes that
Conrad III of Germany was the 93rd emperor since
Augustus, and
Frederick I, Holy Roman Emperor the 94th. However, this unity was shattered by
Pope Gregory VII’s unexpected excommunication of Emperor
Henry IV, Holy Roman Emperor amid the
Investiture Controversy of 1075. Thus, this event would usher in the seventh and final age of human history—a period characterized by constant crises, preceding the arrival of the
Antichrist. This forms the central theme of the eighth and final book of the Chronica.
Gesta Friderici Imperatoris More famously, there is Otto’s work Gesta Friderici imperatoris (Deeds of Emperor Frederick). Commissioned by Frederick I, the book opens with a letter from the emperor to the author. Composed of four books, Gesta has its first two volumes written by Otto himself, while the remaining two (or parts thereof) are attributed to his pupil Ragewin (or Rahewin). Some scholars argue that Otto was also the author of the earlier sections of the third and fourth books. Opening with the conflict between Pope Gregory VII and Emperor Henry IV, the first book traces history up to the death of Conrad III in 1152. Its scope extends beyond German affairs, as the author digresses to recount the preaching of Bernard of Clairvaux, his zeal against heresy, and the condemnation of Pierre Abélard; he also delves into discussions of philosophy and theology. The second book begins with Frederick I’s election in 1152, detailing the first five years of his reign, with a particular focus on his campaigns in Italy. From this point onward (1156), Ragewin took over the writing. Otto’s command of Latin was exceptional, and despite a slight bias toward the Hohenstaufens and minor inaccuracies, Gesta has been described as a model of historical composition. == Notes and references ==