High-reeve is Old English heah-gerefa, and Alfred Smyth thought the style was influenced by the Scottish word mormaer, which possibly has the same meaning ("High Steward").

[7] Though Eadwulf and Ealdred had ruled in the north, in the years running up to 954, southern Northumbria was controlled by the Scandinavians, with power switching between Óláfr Sigtryggsson and Eric of York from the early 940s.

[8] According to Roger of Wendover's Flores historiarum (early 13th century), Oswulf was responsible for a conspiracy with a certain Maccus that led to the betrayal and death of Eric, ruler of York, "in a certain lonely place called Stainmore".

By the twelfth century, there is a tradition that Oswulf was able to take command of all Northumbria, notwithstanding the overlordship of King Eadred, West Saxon ruler of England.

[10] Although this part of the Flores historiarum was compiled centuries later and contains some obvious anachronisms, the author had access to certain earlier sources, no longer extant, making the account credible.

[13] Another twelfth-century source, De primo Saxonum adventu, summarises his status as follows:Primus comitum post Eiricum, quem ultimum regem habuerunt Northymbrenses, Oswulf provincias omnes Northanhymbrorum sub Edrido rege procuravit.First of the earls after Erik, the last king whom the Northumbrians had, Oswulf administered under King Eadred all the provinces of the Northumbrians.

[14] Similar sentiments were expressed in the related Historia Regum: "Here the kings of Northumbrians came to an end and henceforth the province was administered by earls".