Shortly after the beginning of the Saxon wars the king of the Franks received an urgent summons from the pope, who was again being threatened by his old enemies, the Lombards. Charlemagne led a mighty host across the Alps, captured Pavia, where the Lombard ruler had taken refuge, and added his possessions to those of the Franks. Thus passed away one more of the Germanic states which had arisen on the ruins of the Roman Empire. Charlemagne now placed on his own head the famous "Iron Crown," and assumed the title of "King of the Franks and Lombards, and Patrician of the Romans." CHARLEMAGNE'S OTHER CONQUESTS Charlemagne's conquests were not confined to Germanic peoples. He forced the wild Avars, who had advanced from the Caspian into the Danube valley, to acknowledge his supremacy. He compelled various Slavic tribes, including the Bohemians, to pay tribute. He also invaded Spain and wrested from the Moslems the district between the Ebro River and the Pyrenees. By this last conquest Charlemagne may be said to have begun the recovery of the Spanish peninsula from Mohammedan rule. [15] [Illustration: Map, EUROPE In the Age of Charlemagne, 800 A.D.] CHARLEMAGNE'S GOVERNMENT Charlemagne was a statesman, as well as a warrior. He divided his wide dominions into counties, each one ruled by a count, who was expected to keep order and administer justice. The border districts, which lay exposed to invasion, were organized into "marks," under the military supervision of counts of the mark, or margraves (marquises). These officials had so much power and lived so far from the royal court that it was necessary for Charlemagne to appoint special agents, called _missi dominici_ ("the lord's messengers"), to maintain control over them. The _missi_ were usually sent out in pairs, a layman and a bishop or abbot, in order that the one might serve as a check upon the other. They traveled from county to county, bearing the orders of their royal master and making sure that these orders were promptly obeyed. In this way Charlemagne kept well informed as to the condition of affairs throughout his kingdom. REVIVAL OF LEARNING UNDER CHARLEMAGNE