I want to know the answer to the following question:
In what year did the northern parts of the country form the Brythonic kingdom of Rheged?
All the background I'm provided with is that "In the centuries after the Roman withdrawal in 410AD the northern parts of the county probably formed part of the Brythonic kingdom of Rheged, a successor entity to the Brigantes tribe.". Is that enough to answer the question?
Answer: yes