Before Christianity became a force in Europe, many cultures worshiped numerous "gods" and deities. The Greeks, Romans and Egyptians all believed in more than one god and prayed to them for guidance, provision, health and safety. For instance, the Greeks and Romans were host to a multitude of gods; wind, love, and many more. At the command of Pharaohs, Egyptians built magnificent temples specifically designed for worshiping their deities. .
During the middle ages (from 500A.D to 1500A.D.) Christianity flourished in Europe. Christians across the continent, both rich and poor, were trading in their beliefs in mythologies and turning their attentions to the God of Abraham. Many early Christians were devout and would sacrifice much - including taking long pilgrimages to Jerusalem (the home of Jesus) to pray. It was commonplace for young people to enter religious orders to prepare their lives for priesthood and other roles of ministry and service. .
The second largest group (and by many accounts, most powerful)were Muslims, who conquered Palestine - known to Christians as the Holy Land. However, around 1,000AD, Seljuk Turks came to power in Palestine and refused to allow Christians to come to Jerusalem, or any other holy place to worship. Those who did travel to the Holy Land were caught in the middle of a violent battle between Christians and Muslims that resulted in the death of thousands of Christians making their pilgrimage. The Muslims considered Palestine theirs, and this is how they view it to this day.
At this juncture, many religious leaders were outraged by the Muslim attack on Christians. In 1095AD, Pope Urban was involved in organizing the Crusades, also known as the Holy Wars. Many monks, nuns, queens, knights, lords, and serfs were determined to get back the holy land. However, their objective had failed, resulting in many deaths. The only positive aspect that came from the Crusades was that it allowed trade with Europe and the Middle East.