This was widely felt to be an injustice. When Rudolf died on 16 October of the same year, Henry, now more experienced, took up the struggle. In 1081 he opened the conflict against Gregory in Italy. Gregory had now become less powerful, and thirteen cardinals deserted him. Rome surrendered to the German king, and Guibert of Ravenna enthroned as Clement III (24 March 1084). Henry was crowned emperor by his rival, while Gregory himself had to flee from Rome in the company of his Norman "vassal" Robert Guiscard.