The studies here reflect Jonathan Riley-Smith's work as a historian, which began with research on the history of the military orders, the specific focus of the third section here. Out of this grew the concerns covered in the previous sections: an interest in the political and constitutional history of the kingdom of Jerusalem and the relations of the western settlers with the indigenous population of Palestine and Syria; the theory of crusading, involving research on theology and canon law, and the rôle of the popes as preachers, and at the same time detailed consideration of the responses of lay men and women to the ideas that were being presented to them. The two final papers explore some of the implications of crusading ideology and mythology in the modern world.