The first king of Deira of whom we know was Ella, or Aelle, who, according to Bede, was still reigning when Augustine arrived in 597.
ZEthelfrith eventually acquired possession of Deira, probably in 604 or 605, perhaps on Ella's death, expelling his son Edwin (q.v.).
At his death in 633 the kingdom was again divided, Deira falling to his nephew Osric, while Bernicia was occupied by Eanfrith son of ZEthelfrith.
After Oswald's defeat and death at the hands of Penda in 642 Bernicia fell to his brother Oswio, while Oswine son of Osric became king in Deira, though probably subject to Oswio.
Oswine's death was compassed by Oswio in 651, and the throne of Deira was then obtained by 1-Ethelwald son of Oswald.
He is not mentioned, however, after 655, so it is probable that Deira was incorporated in the Bernician kingdom not long afterwards.
At Gilling in 651 he caused the murder of Oswine, a relative of Edwin, who had become king of Deira, and a few years later took possession of that kingdom.
ZEthelfrith, king of Bernicia, united Deira to his own kingdom, probably about 605, and the union continued under his successor Edwin, son of Ella or Ã†lle, king of Deira.
Bernicia was again separate from Deira under Eanfrith, son of lEthelfrith (633-634), after which date the kings of Bernicia were supreme in Northumbria, though for a short time under Oswio Deira had a king of its own.
The districts north of the Humber contained two kingdoms, Bernicia (q.v.) and Deira, which were eventually united in Northumbria.
Oswald reunited Deira and Bernicia, and soon raised his kingdom to a position equal to.
His relationship to Edwin may have helped him to consolidate Deira and Bernicia.
He became earl of Deira after the death of Eadwulf Cutel, earl of Northumbria, about 1038, and earl of all Northumbria after murdering Eadwulf, earl of Bernicia, in 1041.
The pagan English of Deira (603) routed under lEthelfrith the Christian Scots of Argyll between Liddesdale and North Tyne; and pagan English for more than a century held unopposed the tianity.
He married Acha, daughter of Ella (Ã†lle), king of Deira, whom he succeeded probably in 605, expelling his son Edwin.
DEIRA, the southern of the two English kingdoms afterwards united as Northumbria.
After his death Deira was subject to 2Ethelfrith, king of Northumbria, until the accession of Edwin, in 616 or 617, who ruled both kingdoms (see EowiN) till 633.
Osric the nephew of Edwin ruled Deira (6 33634), but his son Oswine was put to death by Oswio in 651.
For a few years subsequently Deira was governed by lEthelwald son of Oswald.