Flavius Josephus (The Jewish War, 3.3.5) lists the Roman province of Arabia among the toparchies just before the war with Rome. For other references, see Emil Schürer, Geza Vermes and Fergus Millar, The History of the Jewish People in the Age of Jesus Christ, 4 vols. (Edinburgh: T & T Clark, 1973–1987), vol. 2, pp. 190–194.