The document discusses the religious wars known as the Crusades between Christians and Muslims over control of the Holy Land of Palestine from 1095 to the late 1100s. It provides background on how the Muslim conquest of Palestine in 1050 led the Pope to call for the Crusades to drive Muslims out. The first Crusade was initially successful in capturing Jerusalem, but later Crusades resulted in victories for Saladin and the Muslims as he unified Muslim forces and retook the city for Islam. The Crusades established long-term religious conflict between Christians and Muslims over the Holy Land and increased trade and cultural exchange between Europe and the Middle East.