Until recently no coins from Eardwulf's reign were known, which suggested that it may have been a time of instability, or perhaps that the kingdom was impoverished by the payment of tribute to Offa and Coenwulf of Mercia.
Ata que hai pouco se atoparon moedas co nome de Eardwulf, pensábase que fora un período de inestabilidade económica, ou podía ser que o reino se estivese empobrecendo polo pago do tributo a Offa de Mercia e Coenwulf.