Topic: True Brief History of the Crusades
Many people believe that the Crusades were motivated by religion. This is actually false, and I am going to provide you with the actual motivations in a brief summary.
Basically there were three factors:
1. Too many nobles in France and the HRE with nothing to do.
2. Pope Urban II was a ruthless and power hungry mofo.
3. The Byzantine Emperor was frustrated by his losses in Anatolia.
So while the Byzantine Emperor was getting pwned by the Turks in Anatolia, he came up with the brilliant idea of asking the Pope for help. In turn, he promised his empire would make religious accommodations with the pope.
Pope Urban II riled up crowds and calls for a crusade. Since there were plenty of knights with nothing to do in France and the HRE, an army consisting of a horde of peasants and a sizable number of knights was assembled.
The army arrives in Constantinople, and the Emperor is like "Holy crap..." Needless to say, the two sides did not get along from the get go. The crusaders did not approve of the "decadence" of the Byzantine Empire, going to such lengths that they complained that the Byzantines used forks and... bathed!
After being ferried to Anatolia and before the fighting began, the Byzantines and Crusaders learned they differed in how to wage war. The crusaders thought it was appropriate to exterminate and loot cities. The Byzantines preferred to occupy them. So at the battle of Nicaea, as the crusader army was laying siege, the Byzantine Emperor came up with another brilliant idea. "Surrender to me. Or would you rather they flood your city?" And so Nicaea surrendered to the Byzantine Empire, and the crusaders were forbidden to pillage or loot. This further broke down cooperation between the two sides, resulting with the crusaders marching on their own towards Jerusalem. On their march to Jerusalem, the army split in to two separate forces between the peasants and knights. By the time they wasted great effort on useless sieges and sacked Jerusalem, the peasants were pwned and only a small fraction of the knights were still alive.
In the end, the crusaders established the crusader states. Meanwhile, the Byzantine Emperor was relieved the crusaders were no longer causing him headaches, and that they served their purpose of easing the pressure from the Turks. Though they continued to cooperate, there remained deep seated hatred between the two sides.
But then...
Since the rulers of the crusader states failed at diplomacy and military strategy, they were pwned by inferior Muslim forces many decades later. And reclaiming the territories lost from the First Crusade was a major motivation for the subsequent Crusades in the Middle East. Moreover, cooperation became difficult between the Latin and Eastern Christians due to bad blood during and after the First Crusade.
So you as you can see. Religion did not start the Crusades in the Middle East. In fact, it had nothing to do with it. It was started by political maneuvers that were conveniently justified by religion, plain and simple. Politics as usual.