Renaud de Montauban was a legendary knight and Christian saint who lived during the 8th and 9th centuries. Primarily known through the medieval French epic *The Four Sons of Aymon*, he is depicted as a hero of the Carolingian era. According to chivalric romances, he was a soldier and a brother to three other knights who fought against Charlemagne. Later in his life, he transitioned from a warrior to a monk and an architect, ultimately becoming a figure of religious veneration in Germany.