The massacre of 3000 Christian Pilgrims in Jerusalem prompted the first crusade. Once inside the city, the crusaders massacred their enemies without mercy. A terrible slaughter of the infidels took place. For seven days the carnage went on, at the end of which time scarcely any of the Moslem faith were left alive. The Christians took possession of the houses and property of the infidels, each soldier having a right to that which he had first seized and placed his mark upon.
The fall of the city of Edessa, followed by the loss of the entire county of Edessa, aroused western Europe to the danger which threatened the Latin Kingdom of Jerusalem and led to another crusading enterprise. In the interval between the Second and the Third Crusade, the two famed religious military orders, known as the Hospitallers and the Templars, were formed. A little later, during the Third Crusade, still another fraternity, known as the Teutonic Knights was established. They were joined by many of the most illustrious knights of the West, and through the gifts of the pious acquired great wealth, and became possessed of numerous estates and castles in Europe as well as in Asia. Louis and Conrad, with the remnants of their armies, made a joint attack on Damascus, but had to raise the siege after a few days. This closed the crusade. This crusade accomplished nothing.
The Third Crusade was caused by the capture of Jerusalem in 1187 by Saladin, the sultan of Egypt. King Philip Augustus of France, King Richard I of England, and the German emperor, Frederick Barbarossa assumed the cross, and set out, each at the head of a large army, for the recovery of the Holy City of Jerusalem. King Richard and Saladin finally concluded a truce by the terms of which Christians were permitted to visit Jerusalem without paying tribute, that they should have free access to the holy places, and remain in undisturbed possession of the coast from Jaffa to Tyre.
In the Fourth Crusade, the pope lead a number of knights hoping to get to Egypt, the center of Muslim power. They proceeded to Venice where they made an agreement that they would capture Zara ( a Christian city) in return of necessary ships for transportation. However they never made it the Holy Land and I stead were persuaded to turn against Constantinople.
The Fifth Crusade (1216-1220) was led by the kings of Hungary and Cyprus. Its strength was wasted in Egypt, and it resulted in nothing.
The Sixth Crusade (1227-1229), headed by Frederick II. of Germany, succeeded in securing from the Saracens the restoration of Jerusalem, together with several other cities of Palestine.
The Seventh Crusade (1249-1254) was under the lead of Louis IX. Of France, surnamed the Saint.
The leader of the eighth crusade was King Louis IX of France. King Louis IX directed his forces against the Moors about Tunis, in North Africa. Here the king died of the plague. Nothing was effected by this crusade.
The leader of this crusade was Prince Edward of England, afterwards King Edward I. Edward succeeded in capturing Nazareth, and agreed to a treaty favorable to the Christians in the Last Crusade.