Theophilus of Edessa (~695-~785 CE) was a medieval astrologer and scholar from Edessa in northern Mesopotamia ( Hoyland, 2011:6). He is said to have translated books from Greek to Syriac - indicating fluency in both languages ( Hoyland, 2011:7). Although he was a Chalcedonian Christian, he worked later in his life as a court astrologer for Abbasid Caliph al-Mahdi which indicates fluency in Arabic. As a contemporaneous source for events of the 8th century CE ( Hoyland, 2011:6) with prodigious linguistic skills, he could have accessed much information about events of his times. Unfortunately, the Chronicle he wrote in Syriac is lost. However, this Chronicle appears to show up in a number of later sources (e.g. Michael the Syrian, Chronicon Ad Annum 1234, and Agapius of Menbij who directly cited him) and may have been utilized by Theophanes by way of an intermediary. He was also a source for the lost but influential Chronicle of (the real) Dionysius of Tell-Mahre.