 Eardwulf is said by the early 12th-century "Annals of Lindisfarne and Durham" to have married one of Charlemagne's daughters, information not found in other sources.If this is correct she must have been illegitimate, as the marriages of all the legitimate daughters are known.Coenwulf, on the other hand, who became king of Mercia shortly after Eardwulf's accession, is recorded as having fought with Eardwulf in 801.