 However, Liutprand conquered Spoleto, besieged Rome, laid waste the Duchy of Rome, and seized four important frontier fortresses (Blera, Orte, Bomarzo, and Amelia), thereby cutting off communication with Perugia and Ravenna.This caused the pope in 739 to turn for the first time to the powerful Frankish kingdom, under the protection of which Boniface had begun his successful labours as a missionary in Germany.He sent to Charles Martel, "the powerful mayor of the palace" of the Frankish monarchy and the commander of the Franks in the famous battle at Tours, undoubtedly with the consent of the Greek dux, and appealed to him to protect the tomb of the Apostle.