1075 Lay investiture prohibited. Breach between pope and Henry IV.
1076 Henry calls diet at Worms and declares pope deposed. Gregory excommunicates Henry, who is suspended from his royal office by Diet of Tribur.
1077 Henry humbles himself before the pope at Canossa. Gregory establishes the principle of the papal power to judge kings.
1080 Second excommunication of Henry. His adherents call a council and declare Gregory deposed. Election of Guibert, archbishop of Ravenna, Clement III, as anti-pope.
1084 Henry finally takes Rome. Gregory shuts himself in the castle of St. Angelo. Clement crowns Henry emperor. The Normans take Rome. Robert Guiscard releases Gregory, who goes to Salerno and dies the following year. Clement III rules at Rome.
1086 The cardinals elect Desiderius, abbot of Monte Cassino, Victor III, pope. He lives mostly at Monte Cassino.
1087 Death of Victor.
1088 Five months after Victor’s death Eudes, bishop of Ostia, Urban II, is elected pope. He resides at Monte Cassino.
1094 Urban in Rome. Clement holds only the Vatican, St. Angelo, and the Lateran.
1095 Urban preaches the First Crusade in France. Council of Clermont.