In 1099, just over 900 years was the First Crusade to the holy city of Jeruselam. The Crusades were a series of religiously-sanctioned military campaigns waged by much of Latin Christian Europe, particularly the Franks of France and the Holy Roman Empire.
The Jews and Muslims fought together to defend Jerusalem against the invading Franks.
They were unsuccessful though and on 15 July 1099 the crusaders entered the city. They proceeded to massacre the remaining Jewish and Muslim civilians and pillaged or destroyed mosques and the city itself. One historian has written that the “isolation, alienation and fear” felt by the Franks so far from home helps to explain the atrocities they committed, including the cannibalism which was recorded after the Siege of Maarat in 1098. As a result of the First Crusade, several small Crusader states were created, notably the Kingdom of Jerusalem. In the Kingdom of Jerusalem at most 120,000 Franks (predominantly French-speaking Western Christians) ruled over 350,000 Muslims, Jews, and native Eastern Christians.
After gaining control of Jerusalem the Crusaders created four Crusader states: the kingdom of Jerusalem, the County of Edessa, the Principality of Antioch and the County of Tripoli. Initially, Muslims did very little about the Crusader states due to internal conflicts. Eventually, the Muslims began to reunite under the leadership of Imad al-Din Zangi. He began by re-taking Edessa in 1144. It was the first city to fall to the Crusaders, and became the first to be recaptured by the Muslims. This led the Pope to call for a second Crusade.
Once again Religion is followed by violence or should i say leads it, except this time the Jews and Muslims were on the same side.
Perhaps its a good idea to give peace a chance, but im told this is never too simple.