All attempts at peace between the papacy and the German Empire have failed.

Matilda of Tuscany, the chief military supporter of Pope Gregory VII, had blocked the armies of King Henry IV from the western passages over the Apennines, so he had had to approach Rome from Ravenna.

The pope thereupon retires into the exile of the Castel Sant'Angelo and refuses to entertain Henry's overtures, although the latter promises to hand over Guibert of Ravenna as a prisoner, if the sovereign pontiff will only consent to crown him emperor.

Gregory, however, insists as a necessary preliminary that Henry should appear before a council and do penance.

The emperor, while pretending to submit to these terms, tries hard to prevent the meeting of the bishops.

A small number assemble nonetheless, and, in accordance with their wishes, Gregory again excommunicates Henry.

Upon receipt of this news, Henry, after bribing the Romans into surrendering, enters Rome on March 21, 1084, to see that Guibert is enthroned as Clement III as of March 24.