Charlemagne prepared for every emergency. Immediately upon the receipt of Desiderius’s reply, he began a forward movement. He led the main part of his army over Mont Cenis by a route which Desiderius had supposed to be impassable; while his uncle Bernhard with another division crossed Mount Joll. The two divisions met at the southern base of the Alps. No resistance had been offered except at one spot, and that was easily overcome. Charlemagne pressed forward without delay, defeated the Lombard forces of Adalgis and the Frankish leader Ottocar, and advanced to the siege of Pavia,[22] whither Ottocar had fled to join Desiderius. As the siege might be a long one, Charlemagne at the head of one division of his army advanced toward Rome, taking possession, on the way, of many Roman cities which had fallen into the hands of the Lombards. There was as great rejoicing in Rome as there was consternation among the Lombards at Charlemagne’s victorious progress. Preparations were made to welcome the rescuer. Ozanam says: “On Easter Saturday Charlemagne appeared before the gates of Rome. The clergy bearing crosses, the senators and magistrates waving banners, and the children carrying palm branches and singing hymns, went out to meet him. He ascended to the Vatican where Pope Hadrian awaited him. On the following day he donned the tunic and laticlavium and sat in the court of justice. Military authority and civil jurisdiction were exercised alike by patricians.”[23] Shortly after this Charlemagne set out for his uncle’s camp before Pavia. The chronicles of St. Gall describe his arrival. Desiderius, who was shut in there, mounted a high tower with Ottocar, from which he espied Charlemagne’s army approaching in the distance. At first they saw only the war machines. “Is not Charlemagne there with this great expedition?” asked Desiderius. Ottocar replied that he was not. But when Desiderius saw the large force of warriors following, he said, “Surely Charlemagne is among that multitude.” “No, not yet,” said Ottocar. “But what shall we do,” said Desiderius, who was growing very anxious, “if he should come with a still greater number of soldiers?” While he was speaking, the bodyguards appeared, at sight of whom the panic-stricken Desiderius cried out, “There comes Charlemagne.” Ottocar again assured him he was not there. Then came bishops, abbés, the clergy of the royal chapel, and the grandees. Desiderius exclaimed with a groan, “Let us hide ourselves in the bowels of the earth, far away from the sight of this terrible enemy!” Hardly had he uttered these words when they saw something in the west like a black cloud driven by the northeast wind. The glimmer of weapons foretold a day for the doomed city as dark as night. Then Charlemagne himself appeared—that man of iron, iron-helmeted and gauntleted, his breast and shoulders in coat of iron mail, with lance uplifted in his right hand, his left grasping his sword-hilt.