Help arrives for Pope Gregory VII in…

Help arrives for Pope Gregory VII in the person of Robert Guiscard, Norman duke of Apulia, who, having returned home and suppressed the revolts of his nephews and the lords hostile to himself and to Gregory, moves toward Rome with thirty-six thousand men, defeats the pope's enemies, and rescues him in May, forcing Henry to flee towards Civita Castellana.

Gregory's safety is dearly bought, for a rebellion, or seditious tumult (émeute), of the citizens leads to a three-day sack of the city, during which a large part of the city is burned down.