Johannes Zonaras was a member of the political elite during the late 11th and early 12th century CE Byzantine empire, serving as high judge (Great Commander of the Palace Watch) and imperial secretary (First Secretary of the Chancery).  Sometime during the reign of Alexius Comnenus (1081-1118 CE), he was commissioned to write a commentary on the canons of Byzantine church law. Then in his fifties (around 1112 CE), some personal situation compelled him to retire to the monastery of St. Glykeria.  At the urging of his friends, he took up the challenge of writing the Epitome, which he completed sometime before 1134 when he was in his seventies.  

His Epitome of History (Ἐπιτομὴ ἱστοριῶν) chronicles the history of the world from creation to the year 1118 CE.  The work is divided into two portions, the first six books covering Jewish history down to the destruction of Jerusalem under the Roman emperor Titus in 70 CE and the next twelve books offering α history of the Roman world from the kings to the death of the Byzantine emperor Alexius Comnenus.  Zonaras’ universal history is valued for preserving a running account of time periods where the ancient and medieval historical sources are lacking and for reconstructing missing portions of Cassius Dio’s history of the Roman empire.

Banchich, Thomas, and Eugene Lane, trans. The Histories of Zonaras from Alexander Severus to the Death of Theodosius the Great. London and New York: Routledge, 2009.