The Crusades, a series of holy wars between Catholics, Christians and Muslims in the Near East, had a devastating impact on the cities of Antioch, Jerusalem and Constantinople. These Crusades took place over a period of nearly 200 years, from 1096 to 1270, and involved forces from all over Europe. They began following a synod in Clermont, France, when Pope Urban II called together Catholic and Christian church leaders for an impromptu outdoor service.

Clermont

The Crusades were born in Clermont, France, following the 1095 synod, a gathering of church officials held to address corruption within the church. The synod further detailed agreements that would correct this internal corruption. Following the synod, Pope Urban II delivered a historic sermon to the assembled church leaders. He encouraged Christians to embark on an "armed pilgrimage," a journey, to aid their fellow Christians and repel pagans -- any people who were not Catholic or Orthodox Christian -- from Christian lands.

Antioch

On October 20, 1097, the Crusaders' armies of Catholic and Orthodox Christian knights came to Antioch, just east of the Orontes River in Turkey. They attacked across the Orontes, beginning the siege of Antioch. The city was heavily fortified, and the Crusaders were forced to encamp outside its walls and secure nearby fortresses. By the end of December, the Crusaders' supplies were running low, and the Turkish commander felt it was a good time to attack. The Crusaders fended off the attack, driving Turkish forces back so far that some of the Crusaders' army wound up inside the city. Eventually the Crusaders took Antioch, where they were besieged by Turkish reinforcements.

Jerusalem

The First Crusade -- the only truly victorious Crusade -- ended with the taking of Jerusalem in 1099. When the Crusaders arrived, Jerusalem was occupied by Shiite Egyptian Fatimids. The Fatimids knew they could not rely on support from enemy Sunnis in the area, and the Christian armies took advantage of this animosity to force a surrender of the city. Despite assurances of protection in exchange for their surrender, hundreds of Jerusalem's citizens -- men, women and children -- were murdered by Crusaders as they occupied the city.

Constantinople

The taking of Constantinople during the Fourth Crusade was a sort of victory, but only in the sense that the Crusaders won. Constantinople had, over the years, changed hands between Christian European rule and Turkish Muslim rule. In July of 1203, when Crusaders staged their first major assault, the city was under the control of the Christian Orthodox church. Though Pope Innocent III had issued an edict forbidding the now almost entirely Catholic Crusaders from attacking Christian lands, armies were already camped outside Constantinople's walls. The Byzantine emperor Alexius IV had been unable to fulfill his promises to fund the Crusaders, and they were in a desperate position. Army leaders insisted they had a duty to combat these "enemies of God," and against papal will, facing dire circumstances and under repeated assaults from the city, the Crusaders attacked. They were outnumbered, but superior strategies, determination and brutality won them the city.