In the year 1095, there was fighting in the the Christian Byzantine Empire. The people were fighting amongst themselves. Pope Urban II wanted them to stop this continual warfare. It was like a plague upon Europe. Urban also described the Turkish attacks on the Christian Empire. Rather than fight with their fellow Christians, the Pope wanted the people to attack these Turks. From this, the Crusades were born. The people were so moved by Urban's speech, that tens of thousands joined. This led to one of the first expeditions, led by Peter the Hermit. After this the official crusading armies left on their mission. Before they could reach Jerusalem, their ultimate goal, they were engaged in various battles at Nicaea, Dorylaeum and Antioch. Though they endured many hardships along the way, the Crusaders were triumphant in this Crusade.
The battle for Christianity to survive began long before this, however, with the creation of the Muslim religion. Islam, meaning submission to God's will, was taken partly from the Hebrew religion, as was Christianity. They believe there is one true God, and that Mohammed, while not the only prophet, was the last and greatest one. "Like Christianity, Islam taught the brotherhood and equality of all within the Faith: and it gave the simple clansmen of Arabia a unifying force which they had never known before, which made their hardy and warlike qualities a menace to all outside the Muslim fold."1 The Muslims took over the southern half of the Roman world. .
The rest was divided into two parts, the Eastern Empire and the Western, which included France, part of Germany, Italy and Britain. In the East, the empire was based on Constantinople and had a central government ruled by one emperor. The West was made up of small kingdoms ruled by the descendants of barbarian invaders. It had its religious center at Rome, and the people embraced the power of the Pope.