It might be worth checking out prosopographic studies on the crusades and the crusade states, and historians working with prosopograhy. For a start try: - Jonathan Riley-Smith: The First Crusaders, 1095-1131 - Alan Murray: The Crusader Kingdom of Jerusalem: A Dynastic History, 1099-1125 - Mary Whitby (ed): Byzantines and Crusaders in Non-Greek Sources, 1025-1204