Which group was involved in the conflicts that characterized Louis the Pious’s reign?

The correct choice reflects the internal familial strife that characterized Louis the Pious's reign as Holy Roman Emperor. Louis was the son of Charlemagne and, despite attempting to maintain his father’s empire, he faced significant challenges from his own sons, who were involved in conflicts over succession and power. This familial discord was pivotal, as his sons Charlemagne, Lothair, and Louis the German, among others, struggled for control of various regions, leading to civil strife and contributing to the eventual fragmentation of the Carolingian Empire.

Louis tried to establish an equitable division of his realm among his sons, but this often led to rivalries and confrontations. The conflicts among his sons were significant enough to impact the governance of the empire and the loyalty of nobility, showcasing the tensions during his reign. These issues would eventually culminate in the Treaty of Verdun in 843, which divided the empire among his three surviving sons, solidifying the fragmentation that would continue in European politics.