| Term | Definition |
| Papacy | the office, or position, of pope as head of the Catholic Church |
| monarch | King or Queen who was the supreme ruler |
| kings | held political power |
| popes | held religious power |
| excommunicate | cast out |
| Bishop of Constantinople | Christians in eastern Europe recognized him as their leader |
| Roman Catholic | the western half of the church |
| Orthodox | the eastern half of the church |
| Charlemagne | king of the Franks |
| England,France,Holy Roman Empire | kingdoms of the three most powerful kings |
| Pope Gregory VII | disapproved of Emporor Henry IV |
| Emperor Henry IV | German emperor, he urged other bishops to remove the Gregory as pope |
| bull | a letter explaining a religious teaching |
| authority | power, right to rule |
| Pope Leo IX | becane pope in 1049, excommunicated the bishop of Constantinople |
| Saint Peter | first pope, had been the leader of the whole Christian Church |
| Michael Cerularius | Byzantine Patriarch, excommunicated in 1054 |
| Great Schism | cultural and political division between the Orthodox and Catholic parts of Europe |
| 1122 | a new pope and emperor reached a compromise concerning the bishops, they agreed that the church officials would choose all bishops and abbots, but they would have to obey the emperor |
| Middle Ages | pope was head of the church |