Short answers, pulled from the story.
Northumbria existed from 654 to 1066 AD, a span of over four centuries. It began as a unified kingdom in 651 when Oswiu killed the last independent king of Deira, and it ceased to be an independent kingdom in the mid-tenth century when the Danes established the Kingdom of York.
Between the first king Oswiu in 651 and the last Scandinavian king Eric Bloodaxe in 954, there were forty-five rulers of Northumbria. The average reign lasted just six and a half years. Of the twenty-five kings before Danish rule, only four died of natural causes.
A band of Vikings attacked the monastery at Lindisfarne in 793. It was the first Viking raid to significantly affect Northumbria and is considered the beginning of a century of Viking invasions that severely limited the production and survival of Anglo-Saxon material culture, including manuscripts.
The Synod of Whitby was called by King Oswiu in 664 to resolve a dispute between Celtic and Roman Christian practices, particularly over the date of Easter and the Irish form of the tonsure. Oswiu ruled in favour of Roman practice, bringing Northumbria in line with southern England and western Europe. Celtic clergy who refused to conform, including Bishop Colman of Lindisfarne, returned to Iona.
Bede was born in 673 and died in 735, spending his life in Northumbria. His Ecclesiastical History of the English People, completed in 731, is the primary written source for early medieval Northumbria and became a model for later historians. He is considered the most famous author of the Anglo-Saxon period.
The Gosforth Cross is a stone monument dated to the early tenth century, standing 4.4 metres tall. One face depicts the Crucifixion while the other shows scenes from the Norse myth of Ragnarok. It is richly decorated with mythical beasts, Norse gods, and Christian symbolism, and is considered one of the best examples of Anglo-Scandinavian cultural fusion in the Danelaw.