He was probably raised either at the imperial palace, where his mother continued to live until the death of the emperor, or at the monastery of St. Riquier, where his father was lay abbot.
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.
Nithard's work has been described as a "nostalgic lament":[2] In the times of Charles the Great of good memory, who died almost thirty years ago, peace and concord ruled everywhere because our people were treading the one proper way, the way of the common welfare, and thus the way of God.
Once there was abundance and happiness everywhere, now everywhere there is want and sadness The first three of these books were written before Nithard's appointment as lay abbot of St-Riquier in the winter of 842, the fourth and final in spring of 843 after taking up office there.
For the military historian, Nithard's description of the complex exercises of cavalry in Gaul is particularly valuable as a supplement to the account in the Tactical Handbook of Arrian as well as for its insight into Carolingian techniques.