NORTHUMBRIA, one of the most important of the Anglo Saxon kingdoms, extended from the Humber to the Forth (regnum Northanhymbrorum). Originally it comprised two independent kingdoms, Bernicia and Deira (q.v.), each of which had a dynasty of its own. The first known king of the former was Ida, who, according to tradition, acquired the throne in 547 and reigned twelve years. To him the foundation of Bamburgh is attributed. Four of Ida's sons successively occupied his throne : Glappa 56o, Adda 56o-568, Aethelric 568-572 and Theodoric 572-579. Of the first three nothing is known, but Theodoric is said (His toria Brittonum) to have been besieged by the Welsh under Urien in Lindisfarne. Theodoric was succeeded by Frithuwald 579-585/6 and Hussa 586-592/3. Then Aethelfrith (q.v.), son of Aethelric, came to the throne. He greatly extended his territories at the ex pense of the Welsh, and eventually provoked an invasion of Aidan, king of the Scots, whom he defeated at a place called Daegsastan (6o3). 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. Aethelfrith eventually acquired possession of Deira, expelling Aelle's son Edwin (q.v.). Thenceforward, with rare in tervals, the two kingdoms remained united.
Aethelfrith became involved in war with the Welsh towards the end of his reign and captured Chester, probably about 613. Shortly afterwards, in 616, he was slain in battle on the river Idle by Edwin, who was assisted by the East Anglian king Raedwald. Edwin now became king over both Northumbrian provinces. By his time the kingdom must have reached the west coast, as he is said to have conquered the islands of Anglesea and Man. Under Edwin the Northumbrian kingdom became the chief power in the country. At his death in 633 the kingdom was again divided, Deira falling to his nephew Osric, while Bernicia was occupied by Ean frith son of Aethelfrith. Both these kings were slain by Cadwallon in the following year, but shortly afterwards the Welsh king was overthrown by Oswald (q.v.), brother of Eanfrith, who reunited the whole of Northumbria under his sway and acquired a suprem acy analogous to that previously held by Edwin. 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 Aethelwald 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. After Oswio's victory over Penda
in 654-655 he acquired a supremacy over the rest of England similar to that held by his predecessors. The Mercians, however, recovered their independence in 658, and from this time onward Northumbria played little part in the history of southern England. But Oswio and his son Ecgfrith greatly extended their territories towards the north and north-west, making themselves masters of the kingdoms of Strathclyde and Dalriada, as well as of a large part of the Pictish kingdom. Ecgfrith (q.v.), who succeeded on Oswio's death in 671, expelled the Mercians from Lindsey early in his reign, but was in turn defeated by them in 679, his brother Aelfwine being slain. From this time onwards the Humber formed the boundary between the two kingdoms. In 684 we hear of the first English invasion of Ireland, but in the following year Ecgfrith was slain, and his army totally destroyed by the Picts at a place called Nechtansmere (probably Dunnichen Moss in Forfarshire). The Picts and Britons now recovered their independence for Aldfrith, apparently an illegitimate son of Oswio, who succeeded, made no attempt to reconquer them. He was a learned man, and during his reign the Northumbrian kingdom partially recovered its prosperity. He was succeeded in 705 by his son Osred, and under him and his successors Northumbria began rapidly to decline through the vices of its kings. Osred was slain in 716. He was succeeded by Coenred 716-718, and Coenred by Osric 718-729. The next king was Ceolwulf, to whom Bede dedicated his Historia Ecclesiastica in 731. In the same year he was deposed and forced to become a monk, but was socn restored to the throne. In 737 he voluntarily retired to a monastery and left the kingdom to his cousin Eadberht. The latter appears to have been a vigorous ruler in the year 74o we hear of his being involved in war with the Picts. Aethelbald of Mercia seems to have taken advantage of this campaign to ravage Northumbria. In 75o Eadberht is said to have annexed a large part of Ayrshire to his kingdom. Finally in 756, having now allied himself with Oengus king of the Picts, he successfully attacked Dumbarton (Alcluith), the chief town of the Britons of Strathclyde. Eadberht showed considerable independence in his dealings with the church, and his brother Ecgberht was from 734 to 766 archbishop of York. In 758 Ead berht resigned the kingdom to his son Oswulf, and became a monk.