In 786 the entreaties of the pope and the hostile attitude of Arichis II., duke of Benevento, a son-in-law of Desiderius, called the king again into Italy.
Arichis submitted without a struggle, though the basis of Frankish authority in his duchy was far from secure; but in conjunction with Adalgis he sought aid from Constantinople.
After Adelperga had married Arichis, duke of Benevento, Paulus at her request wrote his continuation of Eutropius.
About 776 his brother Arichis had been carried as a prisoner to France, and when five years later the Frankish king visited Rome, Paulus successfully wrote to him on behalf of the captive.
He also wrote many letters, verses and epitaphs, including those of Duke Arichis and of many members of the Carolingian family.