The Co-dependent Rise of the Merovingians and the Church in Rome

The rise of the Merovingians and the Church in Rome was deeply intertwined with the decline of the Roman Empire and the evolution of Christianity. Rome, founded in 753 BC, became a republic by 509 BC and an empire through conquests, peaking under Trajan in the second century AD. By the third century, corruption and instability led Diocletian to split it into Eastern and Western halves in 285 AD. Constantine I, born in 272 AD, emerged as a pivotal figure, ending Christian persecution in the West after becoming emperor in 306 AD and, following his victory at the Battle of Milvian Bridge in 312 AD, embracing Christianity with the Edict of Milan in 313 AD. His unification of the empire in 324 AD and the Council of Nicaea in 325 AD established Nicene Christianity, asserting secular authority over the Church (Caesaropapism). As the Western Empire crumbled – marked by Alaric’s sack of Rome in 410 AD – the Church in Rome struggled, while the Merovingian king Clovis I (466–511 AD) bolstered its survival. Clovis united the Franks, converted from Arian to Nicene Christianity in 496 AD, and allied with the papacy, defeating the Arian Visigoths in 507 AD, thus laying a foundation for mutual growth amid the empire’s collapse and the Eastern Church’s dominance.

Emperor Constantine I's vision before the Battle of Milvian Bridge

This co-dependent relationship evolved further with later Merovingians and Carolingians. Charles Martel (688–741 AD), a Mayor of the Palace without divine kingship rights, expanded Frankish power and protected the Church, defeating the Moors at Tours in 732 AD and aiding the papacy against the Lombards, granting them the Papal States. His son, Pepin III (the Short), orchestrated a coup in 751 AD, deposing the last Merovingian king, Childeric III, with papal approval, establishing the Carolingian dynasty. Crowned by the Pope, Pepin solidified the Church’s authority to anoint kings, with the Franks as its military arm. Pepin’s deal with the Jews of Narbonne in 759 AD – ceding it as a Jewish client-state under Machir, a Davidic descendant – furthered Frankish influence, despite lacking a navy to conquer it outright. This alliance, sealed by intermarriages, shifted power dynamics, reducing Rome’s reliance on the Byzantine East and reinforcing the Pope’s secular and spiritual authority. By Pepin’s death in 768 AD, the Franks, not Byzantines, were seen as Christianity’s defenders, a perception shaped by their ties with both the papacy and, diplomatically, the Abbasid caliphate.

A Pope installing a Frankish king