Northumbria is also used in the names of some North East regional institutions, particularly the police force (Northumbria Police, which covers Northumberland and Tyne and Wear), a university (Northumbria University) based in Newcastle upon Tyne and Northumbria Army Cadet Force, as well as the regionalist Northumbrian Association. The local Environment Agency office, located in Newcastle Business Park, also uses the term Northumbria to describe its patch. Otherwise, the term is not the official name for the UK and EU region of North East England.
The Anglo-Saxon kingdom of Northumbria was originally two kingdoms divided approximately around the River Tees: Bernicia was to the north of the river and Deira to the south. It is possible that both regions originated as native British Kingdoms which the Germanic settlers later conquered, although there is very little information about the infrastructure and culture of the British kingdoms themselves. Much of the evidence for them comes from regional names that are British rather than Anglo-Saxon in origin. The names Deira and Bernicia likely originate from British words, for example, indicating that some British place names retained currency after the Anglo-Saxon migrations to Northumbria. There is also some archeological evidence to support British origins for the polities of Bernicia and Deira. In what would have been southern Bernicia, in the Cheviot Hills, a hill fort at Yeavering called Yeavering Bell contains evidence that it was an important center for first the British and later the Anglo-Saxons. The fort is originally pre-Roman, dating back to the Iron Age at around the first century. In addition to signs of Roman occupation, the site contains evidence of timber buildings that pre-date Germanic settlement in the area that are probably signs of British settlement. Moreover, Brian Hope-Taylor has traced the origins of the name Yeavering, which looks deceptively English, back to the British gafr from Bede’s mention of a township called Gefrin in the same area. Yeavering continued to be an important political center after the Anglo-Saxons began settling in the north, as King Edwin had a royal palace at Yeavering.
Overall, English place-names dominate the Northumbrian landscape, suggesting the prevalence of an Anglo-Saxon elite culture by the time that Bede—one of Anglo-Saxon England’s most prominent historians—was writing in the eighth century. According to Bede, the Angles predominated the Germanic immigrants that settled north of the Humber and gained political prominence during this time period. While the British natives may have partially assimilated into the Northumbrian political structure, relatively contemporary textual sources such as Bede’s Ecclesiastical History of the English People depict relations between Northumbrians and the British as fraught.
The Anglo-Saxon countries of Bernicia and Deira were often in conflict before their eventual semi-permanent unification in 654. Political power in Deira was concentrated in the East Riding of Yorkshire, which included York, the North Yorkshire Moors, and the Vale of York. The political heartlands of Bernicia were the areas around Bamburgh and Lindisfarne, Monkwearmouth and Jarrow, and in Cumbria, west of the Pennines in the area around Carlisle. The name that these two countries eventually united under, Northumbria, may have been coined by Bede and made popular through his Ecclesiastical History of the English People.
Information on the early royal genealogies for Bernicia and Deira comes from Bede’s Ecclesiastical History of the English People and Welsh chronicler Nennius’ Historia Brittonum. According to Nennius, the Bernician royal line begins with Ida, son of Eoppa. Ida reigned for twelve years (beginning in 547) and was able to annex Bamburgh to Bernicia. In Nennius’ genealogy of Deira, a king named Soemil was the first to separate Bernicia and Deira, which could mean that he wrested the kingdom of Deira from the native British. The date of this supposed separation is unknown. The first Deiran king to make an appearance in Bede’s Historia Ecclesiastica Gentis Anglorum is Ælle, the father of the first Christian Northumbrian king Edwin.