This three-volume edition of the History by Nicephorus Gregoras (c. 1295–1360) was edited by Ludwig Schopen (Volumes 1 and 2, 1829–30) and Immanuel Bekker (Volume 3, 1855). The astronomer and historian, Gregpras, became the archivist of the Byzantine Emperor Andronikos II Palaiologos (to whom he proposed a calendar reform similar to that adopted by Pope Gregory XIII in 1582), and was involved in the fruitless negotiations of 1333 to unite the Greek and Latin Churches. The thirty-seven books of Gregoras' History overlap with the work by George Pachymeres, and continue the narrative to 1359. This period is also covered in the History by the ex-Emperor John Cantacuzene, and both these authors are also reissued in this series. The Latin introduction to Volume 1 includes a life and bibliography of Gregoras, and the Greek text (with Latin translation) begins with the capture of Constantinople by the Franks in 1204.