The kingdom of Northumbria originally consisted of the two independent kingdoms of Bernicia and Deira. Bede writes that Ida was the earliest king of Bernicia. In the early seventh century, Ethelfrith expelled the heir to Deira and ruled over both Bernicia and Deira for the first time, forming Northumbria. A few decades later, Oswald expanded the kingdom considerably west and north, covering the south-east portion of modern day Scotland. Oswald re-introduced Christianity to his people and appointed St. Aidan to establish the monastery of Lindisfarne.
After Oswald’s death, Oswiu gained control of Mercia, making him the most powerful king in England. In the 650s, however, Northumbria lost control of Mercia once again. The kingdom was still extremely powerful until it suffered a crushing defeat at the hands of the Picts at the Battle of Dun Nechtain in 685. From this point, the power of Northumbria seemed to gradually decline.
Fast forward two centuries to the Danish invasion of England. In 867, Halfdan Ragnarsson and Ivar the Boneless conquered Northumbria and installed a puppet king, Ecgberht, on the throne. For about 100 years, the kingdom passed between English and Danish rulers until Eadred finally took over after the death of the kingdom’s last independent monarch. Northumbria was now part of the greater English kingdom.
Additional reading:
- Colls, Robert, Northumbria: history and identity, 547-2000 (2007)
- Higham, N.J., The Kingdom of Northumbria AD 350–1100 (1993)
- Rollason, D., Northumbria, 500–1100: Creation and Destruction of a Kingdom (2003)