Final answer:
The Annals of St. Bertin reference King Louis the Pious, who is known for his religious and intellectual initiatives, but faced significant challenges with his kingdom's security and his sons' rebellion that led to the Treaty of Verdan.
Step-by-step explanation:
The king referenced in the annals of St. Bertin is Louis the Pious, son of Charlemagne. Among his many important attributes, Louis promoted intellectual and religious projects but faced significant challenges in maintaining the unity of his kingdom. During his reign, the weaknesses of the Carolingian state became apparent and his sons, eager to rule, rebelled against him. This culminated in the Treaty of Verdun in 843, which divided the empire among his sons.
He contrasts starkly with later French rulers such as Phillip IV, who drastically changed the French crown's relationship with the church, and , who faced the violent religious dispute between the Catholic majority and Protestant Huguenots, culminating in the issuance of the Edict of Nantes in 1598.
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