Secular-Religious Power Struggle (investiture conflict)

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.