To address fairandbalancedmyass, just because one follows a religion, does not mean that they follow it's rules. This applies not only to Islam, but to Christianity and all religions. There are always bad eggs. But the pilgrims that were trying to visit their holy places WERE killed by followers of Islam. But those that lived in the Middle East just had to visit Jerusalem, and nothing more, they were discriminated against at all. So I think the Pope made the right call in allowing the crusades to happen, because of the horrid acts against Christians that were happening.
Just ask yourself, would there have been any crusade at all if not for Islam and its combative, murderous aggression toward the west? Follow all the history of Islam until we said enough already and decided it was time to push back. People need to call a spade a spade here.
First off, may I just say that I do not believe that the crusades were Christian or at the least justifiable. But ever since 600AD, the Muslims began slaughtering and overrunning Christians in Egypt, Palestine, Asia Minor and even Spain. Almost 2/3 of Christian lands had been conquered by the Muslims and they were no preparing to invade the mainland. Another misconception is that the Christians were taken care of on their pilgrimages, but the opposite is true. Over 30,000 churches had been burned down and over 3000 christians had been murdered in Jerusalem. The Crusades were an act of defense long overdue.
I have a few points to make.
1) No act of 'self defense' can involve 30,000 soldiers marching across the world to go to war. Maybe it's retaliatory, but its not self defense.
2) Your facts are fundamentally incorrect. The pilgrims killed by Muslims in Egypt and the Near East were, quite often violent and antagonistic towards Muslims. Also, the type of Islam prominent at the time specifically forbade the burning/desecration of the holy places of other faiths.
3) Saying those lands were Christian is incredibly hypocritical. Not only was Christianity not the original faith in that area, but Christains had 'conquered' those same lands not a thousand years earlier. The taking of Christian lands by Muslims is a repeat of Christians doing the very same thing to whoever had been there first.