Originally posted by Vrylakas
The historian and Islamic specialist Bernard Lewis describes the Crusades as a Christian retaliatory Holy War, responding to the initial Islamic Holy War. The Moslems burst out of Arabia in the mid 7th century and conquered much of the old Mediterranean world including several Christian kingdoms. Iberia was attacked and overrun in 711, and while the Moslems were turned back at Tours eventually they still maintained a presence on the Rhone River for a century afterward. Southern Italy was attacked, Rome itself was sacked by Arab armies, Sicily was conquered by the Moslems, while Byzantium and Khazaria in the east came under Moslem assault. Pope Stephen's secret journey to the Franks for aid in the 8th century was motivated by a fear of both the Lombards and the Moslems.
The first Islamic empire began a slide into disintegration right about the time the First Crusade was launched - witness the lack of aid other Moslem lands lent the Levante states for the first several Crusades - and had finally stopped expanding. In the meantime since the initial Moslem attacks on Europe, states had begun to evolve out of the barbarian tribal morass and a formal Church structure had been established. By 1100 Europe, entrenched in its Christian identity and still materially poorer than the Moslem world, had organized itself and was accutely aware of the loss of the older Christian areas of the eastern and southern Mediterranean. Lewis posits that while there was a single incident (Moslem defacement of the Church of the Holy Sepulchre in Jerusalem) that led to the call for the Crusades, the real religious zeal behind the Crusaders was motivated by their desire to "recover" Christian Syria, Egypt, North Africa, and the Lebanon. This doesn't mean that many of the Crusaders weren't motivated by the usual greed for land, wealth, booty, etc., but that there was a very fundamental difference between the motivations for Crusaders in 1100 and, say, the French of 1798 who invaded Egypt. very different indeed, though some choose not to distinguish.