- Pope Urban II
- European knights and nobles
- Peasants and commoners
- Byzantine emperor Alexius I Comnenus
- Seljuk Turks
Results:
- Capture of Jerusalem and establishment of the Kingdom of Jerusalem
- Increased power and influence of the Catholic Church
- Cultural and scientific exchange between Europe and the Middle East
- Rise of the Crusades as a religious and political movement
- Conflict and tension between Christians, Muslims, and Jews in the Holy Land