All we know for sure about King Eadwulf of Northumbria (r. 704-705) is found in Stephan’s Life of Wilfrid.
After King Aldfrith’s death in December 704:
“Eadwulf succeeded him for a short while. Our holy bishop, who was at Ripon with Eadwulf’s son, sent messengers to him as a friend — only to be answered with extreme harshness, for the deep rooted malice of Eadwulf’s counselors had turned him against Wilfrid. This was his reply:
‘I swear on my life that if you are not out of my kingdom within six days, you and any of your companions I can find shall perish.’
Shortly afterwards a conspiracy was hatched against the king and he was driven out after a mere two months’ reign. The boy Osred , Aldfrith’s son, took his place and became our bishop’s adopted son.” (V. Wilfrid Ch. 59; Farmer trans, Age of Bede p. 173)
It is often asserted that Eadwulf was a usurper, but this seems unfounded. His successor Osred was a boy of only 8 years old, the first known child-king among the Anglo-Saxons. Therefore, it is likely that Aldfrith left no obvious heir or successor to be usurped! Eadwulf was probably one of the ealdormen of Northumbria who may have held the title sub-king and given his association with Ripon, perhaps in southwestern Northumbria. Just as Ealdorman Berhtfrith is usually associated with the frontier of Lothian, it is possible that Eanwulf’s family was associated with the southwestern frontier of Ripon (Craven and further west).
The conspiracy that toppled his regime was almost certainly orchestrated by Ealdorman Berhtfrith, who essentially became the man behind the throne of the child Osred. If he had been left as Osred’s guardian this might imply that he was a kinsman of King Aldfrith through a female line. We should not forget that female links are the invisible web that held early medieval society together. We don’t know how many more daughters or granddaughters Oswiu might have had, or if Oswald had daughters. A lineage whose name all alliterate with B held the sub-king status since at least the time of Ecgfrith, who would have needed to use his sisters and cousins to support his newly widened powers over all of Northumbria.
The fate of Eadwulf after about February 705 is insecure. There is a line in the Annals of Ulster in 717: “Etulb m. Ecuilb obiit” that might be Eadwulf’s death [death of Eadwulf son of Ecgwulf?]. This is one year after the murder of Aldfrith’s 19 year old son King Osred that has long been credited to his successor Coenred. It is possible that Osred could have been murdered by Eadwulf’s faction in a bid to retake the throne? If so, then it failed and the grandsons of Leodwald — Coenred, Coelwulf, and Eadberht– competed over the throne for the rest of the century.
The old lineages of Aldfrith and Eadwulf were not out of the running yet. Aldfrith’s second son Osric succeeded Coenred, but named Coelwulf his heir. King Eadberht executed two notable ealdormen, Earnwine (son of Eadwulf?) and Offa son of Aldfrith, ending Aldfrith’s lineage, as far as we know (although, again, female linkages to the old Aethelfrithing royal line may have lead to key political claims). Eadwulf has also been suggested to be the ancestor of late eighth century kings Eardwulf and Eanred.