What were the crusades? -- A just cause. A just cause for war ; Crusades to the Near East ; Crusades in Spain ; Crusades in North-eastern Europe ; Crusades against schismatics and heretics ; Crusades against lay powers in the West ; A cause for a crusade -- Legitimate authority. Papal authorisation ; Peace in Christendom ; Preaching ; Finance ; Strategy ; Control -- Who were the crusaders? The vow ; Privileges ; Who were the crusaders? ; Geoffrey of Sergines ; The military orders -- When were the crusades?