Carloman was the eldest son of Charles Martel, mayor of the palace and duke of the Franks, and his wife Chrotrud of Treves. On Charles's death (741), Carloman and his brother Pepin the Short succeeded to their father's legal positions, Carloman in Austrasia, and Pepin in Neustria. He was a member of the family later called the Carolingians and it can be argued that he was instrumental in consolidating their power at the expense of the ruling Merovingian kings of the Franks. He withdrew from public life in 747 to take up the monastic habit, "the first of a new type of saintly king", according to Norman Cantor, "more interested in religious devotion than royal power, who frequently appeared in the following three centuries and who was an indication of the growing impact of Christian piety on Germanic society".

Charles Martel, Martel being a sobriquet in Old French for "The Hammer", was a Frankish political and military leader who, as Duke and Prince of the Franks and Mayor of the Palace, was the de facto ruler of the Franks from 718 until his death. He was a son of the Frankish statesman Pepin of Herstal and a noblewoman named Alpaida. Charles successfully asserted his claims to power as successor to his father as the power behind the throne in Frankish politics. Continuing and building on his father's work, he restored centralized government in Francia and began the series of military campaigns that re-established the Franks as the undisputed masters of all Gaul. According to a near-contemporary source, the Liber Historiae Francorum, Charles was "a warrior who was uncommonly ... effective in battle".