In 1000's in the Europe, the people were uneducated. They were poor. The rich and noble people didn't think about that people. Misery was happening in Europe. In the churches people were trying to worship, but the clergy were lying and tricking these people. There were social classification all over the Europe. The aristocratics and clergy could make everything what they wanted. Poor people were doing everything for a good life. Also they were stealing money and food and killing people to get their money. At other side in East everything was perfect. The social culture, the science, the education, the medicine, the art and the other things were better than Europe. There were no social classification. People were in peace. Many people were Muslims in East, but they were respectful to other religions and people. That situation wasn't good for European people. They were angry and jealous. Also the holy place Jerusalem was in East and the Muslims were living there. They needed to do something. They decided to create crusader army.
The Pope Urban II created chaos for the poor public. He said that the Muslims were doing torture to Christians in East and in Jerusalem. Also he added that the Muslims weren't real owners of Jerusalem. He told they were destroying the city. He tried to trick them for a war. He said God will forgive them because of their crimes and sins. He created a very big army after that call. The poor people saw that a real change for their life. The main problem was the Seljuq Turks in Anatolia. They were a danger for Europe and the Byzantine Empire, so Byzantine Empire wanted help from Pope, and Pope Urban II planned to did everything in one time, so he accepted that call. Everything was starting after that events.