Professor Shahid was one of the readers of my doctoral dissertation.Though he was the definitive historian of Byzantine-Arab relations down to the Islamic conquests, he didn't actually teach history at Georgetown, where he was the Oman Professor of Arabic and Islamic Literature, teaching the Qur'an, Classical Arabic Literature, and the like in the Arabic department. I really only got to know him from his eager involvement in my doctoral committee.
Born as Irfan Kawar in Nazareth in 1926 to a Palestinian Greek Orthodox family, he read Classics at Oxford and then took his Ph.D. at Princeton in Arabic and Islamic studies. I never did know why he changed his name from Kawar to Shahid.
Although he was a prominent enough figure at Georgetown, I suspect he was really far more at home at Dumbarton Oaks, the Harvard-owned Byzantine studies library in Washington, where he did most of his life's work on Byzantium and the Arabs. He discussed his time there in an interview at Dumbarton Oaks in 2008. His publications included Rome and the Arabs: A Prolegomenon to the Study of Byzantium and the Arabs; Byzantium and the Arabs in the Fourth Century, Byzantium and the Arabs in the Fifth Century; and Byzantium and the Arabs in the Sixth Century, and numerous articles. I am uncertain if his final volume, on the seventh century and the Arab Conquests, might have been far enough along to someday appear. Unfortunately, all his volumes are priced beyond my or most people's reach.