As the genius of Robert expanded with his fortune, he awakened the jealousy of his elder brother, by whom, in a transient quarrel, his life was threatened and his liberty restrained. After the death of Humphrey the tender age of his sons excluded them from the command; they were reduced to a private estate by the ambition of their guardian and uncle, and Guiscard was exalted on a buckler and saluted Count of Apulia and general of the republic. With an increase of authority and of force he resumed the conquest of Calabria, and soon aspired to a rank that should raise him forever above the heads of his equals. By some acts of rapine or sacrilege he had incurred a papal excommunication, but Nicholas II was easily persuaded that the divisions of friends could terminate only in their mutual prejudice; that the Normans were the faithful champions of the Holy See, and it was safer to trust the alliance of a prince than the caprice of an aristocracy. A synod of one hundred bishops was convened at Melphi, and the count interrupted an important enterprise to guard the person and execute the decrees of the Roman pontiff. His gratitude and policy conferred on Robert and his posterity the ducal title, with the investiture of Apulia, Calabria, and all the lands, both in Italy and Sicily, which his sword could rescue from the schismatic Greeks and the unbelieving Saracens. This apostolic sanction might justify his arms, but the obedience of a free and victorious people could not be transferred without their consent, and Guiscard dissembled his elevation till the ensuing campaign had been illustrated by the conquest of Consenza and Reggio. In the hour of triumph he assembled his troops, and solicited the Normans to confirm by their suffrage the judgment of the vicar of Christ; the soldiers hailed with joyful acclamations their valiant duke, and the counts, his former equals, pronounced the oath of fidelity with hollow smiles and secret indignation.