In 978 Otto marched with a great army almost to the walls of Paris to avenge on the Carolingian king, Lothair, his attempt to withdraw Lorraine from the imperial obedience [see page 70]. Few of his acts bring out more clearly his imperial position than this long progress through hostile territory. But Italy was the scene of Otto II.’s most famous actions, and best illustrates his high conception of the imperial dignity. Rome was, as usual, a constant source of trouble. A series of insignificant Pontiffs succeeded John XIII.; but above them towered the noble Roman, Crescentius, Duke of the Romans, perhaps the son of the younger Theodora, Marozia’s sister, who aspired to renew the great part played by Alberic II. [Sidenote: Crescentius at Rome, 980.] In 980 Otto crossed the Alps for Italy, and on his approach the opposition was shattered. In 981 he restored the Pope to Rome, whence he had fled from fear of Crescentius, and forced Crescentius himself to withdraw into the seclusion of a monastery, where a few years later he died. The need of protection still kept the Papacy faithful to the imperial alliance. Otto now assumed new responsibilities directly flowing from his position as Emperor. The Mohammedan lords of Sicily had re-established themselves in southern Italy, and threatened the march of Benevento. Otto marched to the help of the Lombard Duke of Benevento. [Sidenote: Campaigns against Greeks and Saracens, 981–982.] At the same time he sought to make a reality of the cession of Greek Italy, the promised portion of Theophano, but which, owing to the unwillingness of the Byzantines, had never actually come into his hands. In 981 and 982 Otto carried on successful war in southern Italy. A whole series of Greek towns—Salerno, Bari, Taranto—fell into his hands. In the summer of 982 Otto traversed the old road of Pyrrhus, along the Gulf of Taranto, and defeated the Arabs at Cotrone (the ancient Croton), slaying Abul Cassim, the Ameer of Sicily, in the fight. A few days later Otto fell into a Saracen ambush as he pursued his route along the narrow road between the Calabrian mountains and the sea. His army was almost destroyed, though he himself, after a series of remarkable adventures, succeeded in eluding his enemies. [Sidenote: Diet of Verona and projected Crusade, 983.]