In 687, Pippin of Herstal, mayor of the palace of Austrasia, ended the strife between various kings and their mayors with his victory at Tertry and became the sole governor of the entire Frankish kingdom.[4] Pippin himself was the grandson of two of the most important figures of the Austrasian Kingdom, Saint Arnulf of Metz and Pippin of Landen. Pippin of Herstal was eventually succeeded by his illegitimate son Charles, later known as Charles Martel.
After 737, Charles governed the Franks without a king on the throne but declined to call himself king. Charles was succeeded in 741 by his sons Carloman and Pepin the Short, the father of Charlemagne. To curb separatism in the periphery of the realm, in 743 the brothers placed on the throne Childeric III, who was to be the last Merovingian king. After Carloman resigned office in 746 to enter the church by preference as a monk, Pepin brought the question of the kingship before Pope Zachary, asking whether it was logical for a king to have no royal power. The pope handed down his decision in 749. He decreed that it was better for Pepin, who had the powers of high office as Mayor, to be called king, so as not to confuse the hierarchy. He therefore ordered him to become true king.[5]
In 750, Pepin was elected by an assembly of the Franks, anointed by the archbishop, and then raised to the office of king. Branding Childeric III as "the false king," the Pope ordered him into a monastery. Thus was the Merovingian dynasty replaced by the Carolingian