Thomas C. Van Cleve (1969), "The Crusade of Frederick II,"The Later Crusades, 1189–1311, R. L. Wolff and H. W. Hazard, edd., A History of the Crusades, vol. II, Kenneth M. Setton, gen. ed. (Madison, Wisconsin: University of Wisconsin Press), 450–52.
Mary Nickerson Hardwicke (1969), "The Crusader States, 1192–1243,"Later Crusades, 1189–1311, R. L. Wolff and H. W. Hazard, edd., A History of the Crusades, vol. II, Kenneth M. Setton, gen. ed. (Madison, Wisconsin: University of Wisconsin Press), 543.
According to Jean Richard (1985), "The Political and Ecclesiastical Organization of the Crusader States,"The Impact of the Crusades on the Near East, N. P. Zacour and H. W. Hazard, ed. A History of the Crusades, vol. V (Madison, Wisconsin: University of Wisconsin Press), 205, this division of the bailiwick between Acre and Tyre was proposed to Frederick by the Pope. In Les Gestes des Chiprois, Frederick contemplates sending a bailie to Acre and Richart Philangier fust a Sur (Syria) as early as 1233.
