Lay investiture
Ceremonies conducted by kings/nobles to appoint church officials, granting them significant control over the clergy.
Gregory VII vs Henry IV
Conflict between Pope Gregory VII and King Henry IV over lay investiture, leading to Gregory abolishing it and Henry opposing this decision.
Excommunication
The act of officially excluding someone from participation in the Church, as Pope Gregory VII did to King Henry IV for defying the ban on lay investiture.
Resolution/Compromise
The agreement that only the church can appoint bishops, but nobles retain the right to veto appointments, resolving the lay investiture controversy.