Answer:
Due to desire of Charlemagne to revive the ancient Roman culture.
Step-by-step explanation:
This revival of the ancient Roman past have a great impact on Carolingian art because this art was made after the fall of roman empire during the Frankish empire. When the franks defeated the roman empire, they build such type of Carolingian art in their centers which has greatly influenced from ancient roman art. Charlemagne desire to revive the ancient Roman culture so the artists of his empire made arts which reflects the ancient Roman culture.