Byzantine historian and author of a world chronicle of events from the creation to the reign of the Roman emperor Diocletian (reigned 284–305). Together with the parallel work by Eusebius of Caesarea, George's work constitutes the prime instrument for interpreting Christian chronography concerning the primitive church.

Having first lived in the Holy Land of Palestine, George became private secretary to Tarasius, patriarch of Constantinople (reigned 784–806), thus acquiring the title Syncellus (Greek: Cellmate), an official Byzantine position of cleric confidant to a high ecclesiastic. After the death of Tarasius, George retired to a monastery and composed his “Chronicle,” which treats extensively of Christ's birth and the New Testament period but gives scant attention to the post-apostolic age. Following George's death, his “Chronicle” was extended by Theophanes the Confessor to his own time (813); subsequent contributors carried it to the year 961.