In 1094 what exactly caused Byzantine emperor Alexius Comnenus to ask western Christendom for help against the Islamic invaders?
The difference between what started the Christian Crusades and Jihad is that the former was a defense against the latter.
the crusade's real purpose was to turn back Muslim conquests. The entire history of the crusades is one of Western reaction to Muslim conquest, the crusades were no more offensive than was the American invasion of Normandy.
http://www.youtube.com/watch?v=1WZYZ...layer_embedded
http://www.youtube.com/watch?v=ZSgpk...eature=related
http://www.youtube.com/watch?v=rweS_...eature=related
http://www.youtube.com/watch?v=6nOg7...eature=related
http://www.youtube.com/watch?v=vUuH2...eature=related
http://www.youtube.com/user/Occident.../6/C8MCl0bHVXo
http://www.youtube.com/user/Occident.../7/tdabtVzZi2E