 Aistulf, King of the Lombards from 749, attacked the remaining Byzantine territories in Italy and even threatened the Byzantine Papacy in Rome.As Pope Zachary expected no help from Constantinople, he forged an alliance with Pepin the Short, the powerful Mayor of the Palace of the Frankish kingdom north of the Alps, whom he legitimized as King of the Franks.In 755, Pepin invaded Italy and forced Aistulf under Frankish suzerainty.