Hieronymus, son of Charles Martel
Hieronymus, was the son of Charles Martel and his mistress Ruodhaid, and so was the brother of Bernard, Abbot of St. Quentin, a key confidant of Louis the Pious, and Remigius, the third Archbishop of Rouen. In 754, Hieronymus was tasked with Fulradus, abbot of St. Denys, and others, to escort Pope Stephen II back to Rome. This was following King Pipin's victorious campaign against his archenemy Aistulf, King of the Lombards. He became lay abbot of the monastery of St. Quentin in the diocese of Noyon. He was succeeded by his son Fulrad.
Hieronymus married Ercheswinda, origins unknown, and they had four children:
Settipani suggests that Boso of Provence descended from Hieronymus, although there does not appear to be any real evidence to support this.