natural son of king Lothaire, was first priest, then canon of Laon; and was elected archbishop of Rheims in 988. But as he had taken the part of prince Charles, his uncle, and had delivered to him the city of Rheims, the king, Hugh Capet, deposed him in 991, and placed upon the archiepiscopal see the celebrated Gerbert (Sylvester II). Imprisoned at Orleans, Arnulf did not recover his liberty until the death of Hugh and the accession of Gerbert to the pontifical throne. He died about the year 1023. Certain letters of his are found in the Spicilegium of D'Achery. See Hoefer, Nouv. Biog. Generale, s.v.