Part I. National Discourse and the Study of the Crusades: 1. From moral failure to a source of pride; 2. The narrative of the Crusades and the nationalist discourse; 3. Nationalist discourse and Crusader archaeology; Part II. Crusader Studies Between Colonialist and Post-Colonialist Discourse: 4. Colonial and anti-colonial interpretations; 5. Who invented the concentric castles?; 6. 'Crusader cities, ' 'Muslim cities, ' and the post-Colonial debate; 7. Crusader castle and Crusader city: is it possible to differentiate between the two?; Part III. Geography of Fear and the Spatial Distribution of Frankish Castles: 8. Borders and their defence; 9. Borders, frontiers, and centres; 10. The geography of fear and the creation of the Frankish Frontier; 11. The distribution of Frankish Castles during the twelfth century; Part IV. The Castle as Dialogue Between Siege Tactics and Defence Strategy: 12. Siege and defence of castles during the First Crusade; 13. Frankish siege tactics; 14. Development of Muslim siege tactics; 15. Sieges of the 1160s and 1170s and the appearance of the concentric castles; 16. The construction of a frontier castle: the case of Vadum Iacob; 17. The last years of the Latin kingdom: a new balance of power; Conclusion.