Under the Merovingian dynasty, the mayor of the palace (maior palatii or maior domus) was the manager of the household of the Frankish king.
During the second half of the seventh century, the office evolved into the "power behind the throne". At that time the mayor of the palace held and wielded the real and effective power to make decisions affecting the kingdom, while the kings were increasingly reduced to performing merely ceremonial functions, which made them little more than figureheads (rois fainéants, 'do-nothing kings'). The office may be compared to that of the peshwa, shōgun, sarvadhikari or prime minister, all of which have similarly been the real powers behind some ceremonial monarchs.
In 687, after victory over the western kingdom of Neustria, the Austrasian mayor, Pippin of Herstal, took the title Duke of the Franks to signify his augmented rule. His son and successor, Charles Martel, ruled without elevating a new king during the last four years of his reign (737–741)