At the urgent request of his friend
George Syncellus, Theophanes undertook the continuation of his chronicle, during the years 810-15 (P.G., CVIII, 55), making use of material already prepared by
Syncellus, probably also the extracts from the works of
Socrates Scholasticus, Sozomenus, and
Theodoret, made by Theodore Lector, and the city chronicle of Constantinople.
Theophanes' chronicle of world events, covering events from the accession of
Diocletian in
284 (the point where the chronicle of
George Syncellus ends) to the downfall of
Michael I Rhangabes in
813, is valuable for preserving the accounts of lost authorities on Byzantine history that would be otherwise lost for the
seventh and
eighth centuries. The language occupies a place midway between the stiff ecclesiastical and the vulgar Greek.
The work consists of two parts, the first giving the history, arranged according to years, the other containing chronological tables, full of inaccuracies. It seems that Theophanes had only prepared the tables, leaving vacant spaces for the proper dates, but that these had been filled out by someone else (
Hugo von Hurter, Nomenclator literarius recentioris I, Innsbruck, 1903, 735). In chronology, in addition to reckoning by the years of the world and the Christian era, Theophanes introduces in tabular form the regnal years of the Roman emperors, of the Persian kings and Arab caliphs, and of the five oecumenical patriarchs, a system which leads to considerable confusion, and therefore of little value.
The first part, though lacking in critical insight and chronological accuracy, which could scarcely be expected from a man of such ascetical disposition, greatly surpasses the majority of Byzantine chronicles (Krumbacher, "Geschichte der byzant. Litteratur," 1897, 342). Theophanes's Chronicle becomes valuable with the reign of
Justin II (565) the point in his work he drew upon sources that have not survived his times.
His Chronicle was much used by succeeding chroniclers, and in 873-875 a
Latin compilation (published in vol. ii. of De Boor's edition) was made by the
papal librarian
Anastasius from the chronicles of
Patriarch Nicephorus, George Syncellus, and Theophanes for the use of a deacon named Johannes in the second half of the
ninth century, and thus was known to Western Europe.
There also survives a further continuation, in six books, of the Chronicle down to the year 961 written by a number of mostly anonymous writers (called
Theophanes Continuatus or
Scriptores post Theophanem), who undertook the work at the instructions of
Constantine Porphyrogenitus.