Charlemagne reviewed his forces at Regensburg before entering upon his campaign. Upon this occasion he buckled a sword around his third son Ludwig, then thirteen years of age, who was to take part in the expedition. He moved along both banks of the Danube in an easterly direction, while Pepin made his advance from Italy. The Khan of the Avars attacked the latter and was defeated in a bloody battle. When Charlemagne reached the Enns he heard the news and invaded the enemy’s country at once. Several rings were carried by storm, the contents of the treasure vaults removed, the villages devastated, and large numbers of prisoners were taken. A sickness which broke out among the army horses forced the King to retire sooner then he had intended. The war, however, lasted some years longer before the enemy was entirely subjugated. The decisive battle occurred in the year 796. The rings which Pepin had reconstructed, as well as those which remained in possession of the enemy after the first expedition, were taken by assault. Wien[41] was one of the principal localities occupied by the Avars. Charlemagne made the Avar country the Oestmark of the kingdom, subsequently called Oesterrichi and at a later period Oesterreich.[42] Chapter VII The Coronation at Rome Pope Hadrian died at the close of the year 795. Charlemagne was so overcome by the death of the venerable prelate that he shed tears when the sad news was told him. Hadrian had looked upon him as the defender of the Church; and in his relations to the King there was not a trace of that ambition which characterized later Popes, to the detriment of Christianity. Hadrian’s successor, Leo the Third, hastened to ingratiate himself with Charlemagne. He notified the King of his election and sent him a consecrated silver key as a symbol of his recognition of Charlemagne, both as the ruler of Roman territory and as a world sovereign. It is of importance to understand the relations existing between Charlemagne and the Popes, for they were very different from those which existed between the later Popes and the German rulers. A letter of congratulation sent to Leo by Charlemagne throws some light upon them. It begins: “We have read the letter from Your Highness and listened to the decretals, and we heartily congratulate you upon your unanimous election, the dutiful obedience of your people, and your promises of loyalty to us.” During the next few years there were outbreaks in Saxony and Spain. Wittekind and Albion remained faithful to their promises; but not so some of their people. The disturbances, however, were quelled without much difficulty. The Moors in Spain, also, who had gained some advantages, were speedily overcome.