The Crusades started in 1096 ad. They were basically a series of attempts that the Christians made, to retake possession of the holy land. Just so you know, Catholics are called Christians throughout history. So when I say that the Christians did something, it means Catholics most of the time…
The first crusade was started when the Muslims started to take over Eastern Europe, and began treating the Christians in that territory quite badly. They even took over the holy land. Urban II was the Pope at this time, and finally he got fed up with the Christians getting treated badly. He made a very famous speech, calling everyone to arms to go and help their brothers in the holy land. He ended it with the words “Deus vult”, meaning “God wills it!” The crusaders main goal was to recapture Jerusalem. On their first try, they weren’t able to capture it. On their second try they were successful, and captured their goal; Jerusalem! This crusade was very successful.
This crusade was a disaster! It lasted from 1144-1149. The main goal was to recapture Edessa; which was a complete failure. The crusaders that were still alive after the fighting had to march back to Europe without control of Edessa.
This crusade was a little bit more successful. Saladin (who was the sultan of Egypt) had taken Jerusalem from the Christians. Richard the Lion-heart of England, Frederick Barbarossa of Germany, and Philip Augustus of France were the leaders of this crusade. However, Frederick died before he even got out of his home country, so really it was Richard and Philip that led it. They got into the holy land, defeated Saladin and captured the city of Arsuf. This left a clear path to Jerusalem. However, on the first attempt to capture it, the weather kept them away. On their second try, there was discord among the leaders, so they retreated. Saladin took advantage of this division, and attacked Richards HQ in Jaffa. Richard promptly got it back, and he and Saladin made a peace treaty that ended the crusade in 1192.
In all, there were nine major crusades, but from the fourth crusade on, they were all failed attempts.