Seljuqs Turcomans invade all of Anatolia C. Alexius Comenus 1081- Renovatio Expansion in Balkans and Anatolia Alexius possibly appealed to the Pope for military aid. New Rome Crusades a reaction to perilous situation of Christians in the East. But more than that. Fatamids Fatamids 969. Attacks by Hakim on Christians 1021.
Crusades are a defense of Jerusalem.
Jerusalem Real or not real - Symbolic importance. What I have described so far is lots of different elements that could come together to create a conflict situation. But for the western fighters it had definite religious overtones. This is connected with the attempt by the Church to Control and Christianize the very strong feudal forces - and stop private warfare. Problem of lawless knights and private warfare.