How did the Seljuk Turks' expansion prompt the First Crusade?

The Seljuk Turks' expansion into Byzantine territory and their control over Jerusalem prompted the First Crusade.

The Seljuk Turks, a nomadic tribe from Central Asia, began to expand their empire in the 11th century, moving into the territories of the Byzantine Empire, which included parts of modern-day Turkey, Greece, and the Balkans. This expansion posed a significant threat to the Byzantine Empire, which was already weakened by internal strife and external pressures. The Byzantine Emperor, Alexius I, appealed to Pope Urban II for help in defending his empire against the Seljuk Turks. This appeal was a significant factor in prompting the First Crusade.

The Seljuk Turks' control over Jerusalem was another key factor. Jerusalem, a city of immense religious significance for Christians, Jews, and Muslims, had been under Muslim control since the 7th century. However, the Seljuk Turks' takeover of the city in the late 11th century was seen as a direct threat to Christian pilgrims who wished to visit the holy sites. Reports of violence against Christian pilgrims and the destruction of Christian holy sites by the Seljuk Turks further inflamed the situation.

Pope Urban II, in response to the appeal from Alexius I and the reports of violence in Jerusalem, called for a holy war, or Crusade, against the Seljuk Turks in 1095. His call was met with enthusiasm by many in Western Europe, who saw the Crusade as a chance to defend their faith, gain wealth and land, and perhaps even earn a place in heaven. The First Crusade, which lasted from 1096 to 1099, resulted in the capture of Jerusalem and the establishment of several Crusader states in the Middle East.

In conclusion, the Seljuk Turks' expansion into Byzantine territory and their control over Jerusalem were key factors in prompting the First Crusade. The appeal of the Byzantine Emperor for help in defending his empire, along with reports of violence against Christian pilgrims in Jerusalem, led Pope Urban II to call for a Crusade against the Seljuk Turks. This call was met with enthusiasm by many in Western Europe, leading to the First Crusade and the establishment of several Crusader states in the Middle East.