on the Exarchate of Ravenna. Gregory's opposition to Byzantine iconoclasm did not stop his lending support to the Byzantine Empire to help in the recapture of Ravenna after it had fallen to the Lombards in around 738. In that same year, Liutprand demanded that the Lombard dukes of Spoleto and Beneventum ravage the area around the Duchy of Rome; but both refused, citing a treaty with the pope. Gregory then actively encouraged the rebellion of Thrasimund, forcing Liutprand to temporarily abandon his attacks on the exarchate, turning his attention towards Spoleto, which Liutprand annexed. Thrasimund was forced to flee Spoleto, seeking refuge in Rome, where he was welcomed by Gregory. By the middle of 739, Liutprand was encroaching once again on the Exarchate and threatening Rome. In desperation, Gregory sent ambassadors to Charles Martel, the Frankish mayor of the Palace, begging him to intervene on the pope’s behalf. Although Gregory stated that he was willing to give up his allegiance to the Eastern Empire and place himself under the protection of the Franks, Charles made no promise to assist, since he was fully occupied by the Umayyad invasion of Gaul. Gregory himself referred to these Saracen Muslims as gens ferocissima or "that most fierce nation". The Lombard capture of the towns of , Ortas, Polimartium and Blera once again caused Gregory to write to Charles, this time in even greater tones of despair, beseeching his aid: Our affliction moves us to write to you once again, trusting that you are a loving son of St. Peter and of us, and that, from respect for him, you will come and defend the Church of God and His peculiar people, who are now unable to endure the persecution and oppression of the Lombards. They have seized the very means set aside to furnish funds for the lights ever kept burning at St. Peter's tomb, and they have carried off offerings that have been made by you and by those who have gone before you. And because, after God, we have turned to you, the Lombards deride and oppress us. Hence the Church of St. Peter has been stripped and reduced to the last straits. We have put into the mouth of the bearer of this letter, your faithful servant all our woes, which he will be able to unfold to you. Please come at once, to show your love towards St. Peter,