prelate, poet, and one of the leading theologians of the Frankish Empire.

A member of Charlemagne's court, Theodulf became bishop of Orléans in 775 and abbot of Saint-Benoît-sur-Loire in 781. He worked for reform of the clergy within his diocese and established a hospice. In 800 he was in Rome for Charlemagne's coronation, and in 804 he succeeded the English scholar Alcuin as Charlemagne's chief theological adviser. Charlemagne involved Theodulf in the dispute concerning the Filioque clause in the Nicene Creed, which describes the procession of the Holy Ghost from the Father “and from the Son” and which is one of the causes of the division between the Greek and Roman churches. At Charlemagne's request, Theodulf defended the Filioque clause in his treatise De Spiritu Sancto (“Concerning the Holy Spirit”). It was also at Charlemagne's urging that Theodulf wrote his treatise on Baptism, De ordine Baptismi (“Concerning the Ordinance of Baptism”). Theodulf received the pallium, the symbol of episcopal authority, from Pope Stephen IV in 816. Charlemagne's son and successor Louis I the Pious, deposed Theodulf in 818 for participation in a revolt by Louis's nephew Bernard and imprisoned him in a monastery in Angers, where he died.

Theodulf's poem Ad Carolum regem (“To Charles the King”) depicts Charlemagne surrounded by family and courtiers. A patron of the arts and a builder and restorer of churches, Theodulf had a palace and chapel built at Germigny-des-Prés c. 806 that survives in the département of Loiret as an important example of Carolingian architecture.