Why was Louis called the Pious?

Louis the Pious, the son of Charlemagne, was called "the Pious" due to his deep commitment to Christianity and his efforts to promote religious reform during his reign. He sought to uphold and spread the teachings of the Church, emphasizing a moral and spiritual life. His piety was also reflected in his attempts to support monastic communities and his involvement in church affairs, which earned him respect as a devout ruler. However, his religious zeal sometimes clashed with his political leadership, leading to challenges in maintaining unity within his empire.