Berthoald (died 622) was the Duke of the Saxons during the reign of the Frankish kings Chlothar II and his son Dagobert I, the last ruling Merovingians.
His story is told in the Liber Historiae Francorum (727) and the Gesta Dagoberti (830s), both sources partial to the Merovingian kings.
In 622, shortly after Chlothar had appointed Dagobert to rule Austrasia, the Frankish kingdom that bordered the Saxons, Berthoald rose in revolt and began marching against him.
In the subsequent battle the Franks were defeated and Dagobert received a strong blow to his helmet, by which a portion of his characteristically long Merovingian hair was lost.
[2] The Saxon episode is described briefly in the tenth-century chronicle of Regino of Prüm, who characteristically gets the date wrong (572): In 869, Hildegar, Bishop of Meaux, composed a Vita Faronis episcopi Meldensis in which he claims that a carmen publicum iuxta rusticitatem (a popular song) celebrating the Frankish victory over Berthoald was still being sung.