The islamofascist narrative is that the trouble between Christians and muslims started with the Crusades. The REAL beginning was when muslim armies swept over the middle east and north africa in the seventh century, conquering mostly Christian lands.
That aside, the OP is exceptionally dimwitted - something that happened 800 years ago is a justification for islamofascist barbarities TODAY???
Are things that happened 50 years ago justification for firebombing mosques? The terrorism goes both ways.