Then the people of Gaul came together, and with the consent of Arnulf, chose duke Odo, son of Robert, a mighty man, to be their king.... He ruled manfully and defended the kingdom against the continual attacks of the Northmen. About the same time, Rudolf, son of Conrad, the nephew of abbot Hugo, seized that part of Provence between the Jura and the Pennine Alps [Upper Burgundy], and in the presence of the nobles and bishops, crowned himself king. ... But when Arnulf heard of this he advanced against Rudolf, who betook himself to the most inaccessible heights and held out there. All his life Arnulf, with his son Zwentibold, made war on Rudolf, but could not overcome him, because he held out in places where only the chamois could go and where the troops of the invaders could not reach him. 23. The Coronation of Arnulf, 896. Regino, M. G. SS. folio, I, p. 607. Arnulf regarded himself as the successor to Karl the Great and attempted to exercise some real authority over the whole empire. This appears in his relations to Odo of France, to the kings of the Burgundies, and to the claimants in Italy. The expedition which he undertook to Italy in order to end the disorders there resulted in his receiving the imperial crown. Anno 896. A second time Arnulf went down into Italy and came to Rome, and with the consent of the pope stormed the city. This was an unheard-of thing, not having happened since Brenno and the Gauls captured Rome many years before the birth of Christ.{54} The mother of Lambert, whom he had left to defend the city, fled with her troops. Arnulf was received into the city with the greatest reverence by pope Formosus and was crowned emperor by him before the altar of St. Peter. But as he returned from Rome he was seized with an illness that troubled him for a long time. {54} Not true; see no. 2, for the sack of Rome by Alaric, 410, and by Geiseric, 455. 24, 25. Rise of the Tribal Duchies in Germany, _ca._ 900. 24. Saxony. Widukind, History of the Saxons, I, c. 16; M. G. SS. folio. III, p. 425.