The initial cause for the crusades is the emperor asked for help. Pope Urban the second thought that by “moving” the Muslims Christianity would be brought back together. The goals of the crusades were economic, social, and political goals as well as religious motives. The Pope wanted to reclaim Palestine because the Muslims controlled it and Christendom had split into Eastern and Western branches in 1054. Kings and the Church saw that the Crusades was a good opportunity to get rid of knights who fought each other.
So the Crusades were basically established at that moment.
The first Crusades began in the year 1097 and it ended in the year 1099. Three armies of knights and people of all classes gathered outside the Constantinople. Most of the Crusaders were French. Some were Bohemian, Germans, Englishmen, Scots, Italians, and Spaniards went. Many of the Crusaders knew nothing about the geography, or the climate. On July 15th 1099 12,000 approached Jerusalem. They won a narrow strip of land.
Sadly in 1144 that same strip of land was reconquered by the Turks. Then the second Crusade was being organized to recapture the city. But they came home defeated. Both sets of Crusades were defeated by the Turks. So the 2nd set of Crusades didn’t win this one. But that did not keep them from trying.
The third Crusades goal was to recapture Jerusalem. It was led by three of Europe’s most powerful monarchs. The three powerful monarchs are Phillip the second, emperor Frederick the first and Richard the Lion-Hearted. Phillip argues with Barbarossa, Barbarossa then drowned on the way so Richard lead the Crusaders to regain the Holy Land of Saladin. Richard and Saladin were both good warriors, so they both agreed to a truce in 1192. But Jerusalem remained under Muslim control.
The effects of the Crusades lessened the power that the Pope had before. It also increased the power of the kings. The trade expanded between Europe and Southwest Asia, some goods that were exchanged were spices, fruit and cloth. Muslims and Christians both benefited. In a way the Crusades were successful but in some cases they weren’t.