Eardwulf is known from two charters, one is undated , but identifies Eardwulf’s father as Eadberht I (a patre meo Eadberhtuo); the other has a date that is incompatible with its witness list ), as it is dated 762, but witnessed by Archbishop Cuðbert, who died in 760; it was also witnessed by King Æðelberht II (Aethilberchtus rex Cantie).
Eardwulf é coñecido a partir de dous documentos, un carece de data, pero identifica ao pai de Eardwulf como Eadberht I (a patre meo Eadberhtuo); o outro ten unha data que é incompatíbel coa súa lista de testemuñas, pois está datado en 762, pero pon como testemuña ao Arcebispo Cuðbert, quen morreu en 760; aparece tamén como testemuña ao rei Æðelberht II (Aethilberchtus rex Cantie).