[Illustration:  BATTLE OF TOURS.]

The Greek Empire sent an officer to govern the extreme South of Italy, which, like Rome and Venice, still owned the Emperor; but all the troops that could be hired were soon wanted to fight with the Arabs, whose false prophet Mahommed had taught them to spread religion with the sword.  There was no one capable of making head against the Lombards, and the Popes only kept them off by treaties and good management; and at last, in 741, Pope Gregory III. put himself under the protection of Charles Martel, the great Frank captain who had beaten the Mahometans at the battle of Tours.  Charles Martel was rewarded by being made a Roman senator, so was his son Pippin, who was also king of the Franks, and his grandson Charles the Great, who had to come often to Italy to protect Rome, and at last broke up the Lombard kingdom, was chosen Roman Emperor as of old, and crowned by Pope Leo III. in the year 800.  From that time there was again the Western Empire, commonly called the Holy Roman Empire, the Emperor, or Caesar—­Kaisar, as the Germans still call him—­being generally also king of Germany and king of Lombardy.  Rome was all this time chiefly under the power of the Popes, who grew in course of years to be more and more of princes, and at the same time to claim more power over the Church, calling themselves Universal Bishops contrary to the teaching of St. Gregory the Great.  All this, however, belongs to the history of Europe in modern times, and will be found in the history of Germany, since there were many struggles between the Popes and Emperors.  For Rome has really had two histories, and those who visit Rome and study the wonderful buildings there may dwell on the old or the new, the pagan or the Christian, as their minds lead them, or else on that strange middle time when idolatry and Christianity were struggling together.