Medieval Crusades
In total there are eight main Crusades and a number of smaller ones. By the end of the 11th century political conditions were relatively stable across Europe. Pilgrimages to Jerusalem were fairly common and the Catholic Church had assumed responsibility for maintaining the holy places along the way. At the end of the 11th century the Catholic Pope was Urban II, and along with Alexius Commenus he instigated the first Crusade in response to local chieftains with in the middle east fighting amongst themselves and endangering the pilgrims in the process.Although the Crusades rarely achieved their military objectives the impact that they had on medieval society was profound. For 350 years they stimulated trade, brought new ideas to your comment and had a lasting influence on food, architecture, furniture and dress.
The first Crusade
Field command was given to Raymond IV, Count of Toulouse. However there was not a great deal of cohesion amongst the Crusaders. Nevertheless they took Jerusalem on the 15th of July 1099 AD. This was celebrated by the massacre of Jews and Muslims. Despite this victory the road to the holy land did not become any safer and for two years later it was decided that another Crusade was necessary.
The second Crusade
This began in 1147 AD when two separate armies marched towards Jerusalem. However both armies were ambushed in no objectives were met. The Saracens were growing in strength and under Saladin they recaptured Jerusalem in October 1187 AD.
The third Crusade
This is raised in response to Saladin's capture of Jerusalem. One of its leaders was Richard the lion heart. The two other notable leaders were Philip Augustus of France and Frederick Barbarosa who enjoy the title of King of Germany as well as that of the holy Roman Emperor.
The first significant military success was when they took the town of Acre. This military action was largely driven by Richard the lion heart. One result of his success was that Philip Augustus sailed back to France where he plotted with John, Richard's brother. When direct outcome of this was the building of Château Gaillard.
After the fall of Acre the crusaders marched along the coast to Jaffa. Subsequently successful along the coast Richard still fail to capture Jerusalem. The Crusade ended with a three-year truce with Saladin.
The fourth Crusade
This was launched about 10 years later by Pope Innocent III. However it never made the holy land as a result of the Venetian Navy requiring payment by attacking cities along the way. This ended with an attack on Constantinople which was sacked and pillaged.
The fifth Crusade
This is Crusade was set the task of capturing Damietta in Egypt. It was believed that the Saracens would then except this city in exchange for Jerusalem. On the 29th of August 1219 AD Damietta was finally entered after a 17 month siege. Unfortunately they decided to press on with the Nile flood devastated their plans and they surrendered Damietta in return for safe journey home.
Later Crusades
These are even less successful and no permanent Christian settlement was established in the holy land.