Southern Italy and Sicily had been allowed to take care of themselves. The Greek emperor had not been able to retain his hold on them, and the German emperor, while claiming them, had never succeeded in extending his power over them. A handful of adventurous Normans had established themselves on the mainland and had assumed the title of counts. Their ambition grew with their fortune; they desired a higher title than count and wished to increase their possessions. So they turned to the pope and asked him to confer upon them the title of duke, and to give them his blessing in their proposed conquest of Sicily, which was in the hands of the Mohammedans. In granting the request of these Normans, the pope assumed the lordship over southern Italy and Sicily, to which he had no right, and thereby put forth claims which conflicted with those of both emperors. For more than two centuries the possession of southern Italy and Sicily was the ground for a bitter struggle between the popes and the German emperors. The importance of this event is seen when we consider that the long struggle between the papacy and the empire was about to begin. The pope had little besides his spiritual weapons (excommunication, interdict) with which to oppose the emperor. But in Robert Guiscard he secured a powerful vassal who was to render him great military aid against the emperor. § 70. I, Robert, by the grace of God and of St. Peter duke of Apulia and Calabria, and with their aid to be duke of Sicily [that is, when I shall have conquered it], in confirmation of the gift and in recognition of my oath of fidelity, promise that from all the lands which I hold under my own sway, and which I have never conceded that anyone from beyond the mountains{70} [Alps, that is, Germany] holds, I will pay annually for each yoke of oxen 12 denarii of the mint of Pavia to you, my lord, Nicholas, pope, and to all your successors, or to your or their legates. And this payment shall be made at the end of the year on easter day. I bind myself and my heirs and my successors to pay this sum to my lord, Nicholas, pope, and to your successors. So help me God and these holy gospels.