What leading palace official held the true power in the Merovingian dynasty?

The leading palace official who held true power during the Merovingian dynasty was the mayor of the palace. This position evolved to become more influential than the Merovingian kings themselves, especially during the 7th century. Notable mayors such as Pepin of Herstal and his grandson Charles Martel effectively controlled the Frankish kingdom, leading to the eventual rise of the Carolingian dynasty.