The First Crusade was launched in 1095, when pope Urban II called for a military expedition to take control of the Holy Land. This inaugurated a period of two centuries in which Christians and Muslims often fought one another – and sometimes their own co-religionists – in the whole region between Anatolia and Palestine, even stretching to Egypt.
Disunity amongst the crusaders arose when Norman Bohemond finally took the city of Antioch, one of the patriarchal sees of Christianity, from the Seljuk, a Turcoman Sunni dynasty. The crusaders had promised the Byzantine emperor to hand back the conquered territories, but Bohemond refused to comply. Shortly after his conquest, an army led by Kerbogha of Mosul retook the city. Eventually, the crusaders managed to re-conquer Antioch, but internal strife broke out. Some stayed, some went on to conquer Palestine, the Holy Land.
Godfrey of Bouillon’s army went south. In the beginning, the Fatimid did not seem overtly distressed by the Crusaders’ passing through their territory. This changed, however, when the Europeans approached Palestine and Egypt. In 1099, Godfrey of Bouillon conquered Jerusalem and established the Latin Kingdom of Jerusalem.
There seemed to be no possibility to stop the Christian variation on the Islamic jihad until 1144, when the Crusaders’ stronghold in Edessa (Şanlıurfa or Urfa in modern Turkey) was captured by Imad al-Din Zengi ibn Aq Sunqur, governor of Mosul. The war against the Crusaders was effectively continued by sultan Salah al-Din Yusuf ibn Ayyub, commonly known as Saladin, who won in 1187 the important Battle of Hattin, that brought most of Palestine under Muslim rule again.
In the Muslim world, there was a patent hostility between Shiite Egypt and Sunnite Baghdad. The emirates located between the two powers – fearing the Turkish Seljuk – remained divided in their allegiance. Eventually, in 1291, it was the Mamluks, a new Egyptian dynasty – though of Turkish origin and Sunnite – who brought the final blow to the Crusaders who were driven out of Acre.
The Crusades lasted two centuries, cost many lives, and brought a lot of destruction, epidemics and disorder. But on the whole, the local inhabitants were allowed to remain true to their faith – except for slaves and prisoners of war. They also retained their local authorities and justice system. In many ways, the eastern and western cultures influenced one another. Trade thrived, especially in the coastal regions. Traders – whether they were Muslims, Christians or Jews – enjoyed special protection when crossing borders, even when they had to enter enemy territory. Caravans crossed the whole region, ships went from Egypt to Tyre to Constantinople and further.
Under the rule of the Mamluks Palestine formed a part of the district of Damascus and initially experienced a short period of relative prosperity. That came to an end, partly because of devastating epidemics as the Great Pestilence that at the same time decimated populations in Europe, partly through an economic deterioration caused by power struggles within the Mamluk regime. In the end, the Mamluks submerged in 1516 against the rising power of the Ottoman (Turkish) Empire.