 The treatise, likely written by the jurist Petrus Crassus, uses arguments based on Roman Law, showing the "Corpus Juris Civilis" had already been studied in Italy.Before returning to Germany, Henry's envoys, Archbishop Liemar of Bremen and Bishop Rupert of Bamberg, raised a rebellion against the Pope's principal Italian ally Matilda of Tuscany.They also secured the support of northern Italian aristocrats for Henry.