Nithard (790-845), a Frankish historian, was the grandson of Charlemagne, by Bertha, a daughter of the great emperor. His father was Angilbert. He appears to have served his cousin, Charles the Bald, on peaceful errands and also on the field of battle. He fought for Charles at Fontenoy in June 841; he died as the result of wounds received whilst fighting for him against the Northmen near Angoulãeme. The date of his death was probably June 14 or May 15, 844 or 845.

"Nithard's historical work consists of four books on the history of the Carolingian empire under the turbulent sons of the emperor Louis I, especially during the troubled period between 840 and 843. The Historiae or De dissensionibus filiorum Ludovici pii (On the Dissensions of the Sons of Louis the Pious) is valuable for the light which it throws upon the causes which led to the disintegration of the Carolingian empire. Although rough in style, partisan in character and sometimes incorrect in detail, the books are the work of a man who had an intimate knowledge of the events which he relates, who possessed a clear and virile mind, and who above all was not a recluse but a man of action. They are dedicated to Charles the Bald, at whose request they were written." [Wikipedia]