 He then refused to commit, as Pope Clement V had requested, to seek a truce with Robert of Naples, and he didn’t rule out attacking the southern kingdom.After Henry concluded a formal treaty signed with Robert's rival to the Sicilian throne, Frederick of Aragon, the chaos in the city of Rome forced Henry to leave, and, following the advice of Tuscan Ghibellines, he travelled north to Arezzo.At Arezzo, in September 1312, Henry proceeded to pass a sentence against Robert of Naples, as a rebel vassal.