King Henry IV

• King Henry IV, Emperor of Rome fought the Pope over Investiture rights
  
• He was excommunicated for attempting to replace Pope Gregory VII 
  
• Pope Gregory went to King Henry's political opponents
  
• In submission, King Henry crossed the Alps in winter to reach Pope Gregory at Castle Canossa, Italy to ask for absolution
  
• King Henry was excommunicated a second time for not cooperating with the Pope in mediating with the German nobles
  
• King Henry invaded Italy and installed Clement III as Pope
  
• King Henry was excommunicated a third time by Pope Gregory for invading Italy
  
• Pope Gregory fled Rome when King Henry sacked it and died a year later