Question: Who is Hieronymus, Son Of Charles Martel's paternal grandfather?
Sentence (from "Hieronymus, son of Charles Martel"): Hieronymus (c. 722 - after 782), 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.
Relevant evidence: Yes