his consequent arrest provoked the rebellion of the anti-imperial faction of the milanese, seen by 19th-century historians as fiercely patriotic. aribert had soon escaped his imprisonment and was leading the revolt from milan. the emperor found himself unable to take milan by siege and proceeded to rome, where his diplomatic skills succeeded in isolating aribert from his erstwhile allies, notably through his famous decree of 28 may 1037, securing the tenancy of lesser vassals, both imperial and ecclesiastical.