Benedict Biscop, ruled Bernicia, a small section of Northumberland between what is now Edinburgh and Newcastle upon Tyne.
According to Bede's writings, Oswy would have been born about 612. Unfortunately for him, his father, King Æthelfrith of Bernicia, was killed in battle against the King of the East Angles, and Oswy and his siblings and their supporters had to flee to exile. They were not able to return to power until 633. Oswy became king when he succeeded his brother Oswald, who died in battle in 642.
In 655, a military victory temporarily made Oswy ruler over much of Britain. This position didn't last very long, but Oswy still remained significant in the larger affairs of Britain. He was especially interested in and supportive of the church. Oswy had been crucial to the foundation of Melrose Abbey. He had allowed his daughter to become a nun. His interest in relics was supported by Pope Vitalian sending him iron filings from the chains that had been used to imprison St. Peter.
In 664, the Synod of Whitby was held to make choices about how Christianity would be practiced, and Oswy was asked to choose. He chose the version of Christianity that was being practiced by Rome over the Celtic version. This also meant calculating the date of Easter differently.
This created some awkwardness; Oswy's son had been raised following Irish-Northumbrian practices but switched to Roman practices at the urging of St. Wilfrid (who was mentioned in a footnote here for his influence on Whitby). Oswy chose to side with his son and Rome, but not everyone found it so easy to switch. Bede reported for 665 "that Easter was kept twice in one year, so that when the King had ended Lent and was keeping Easter, the Queen and her attendants were still fasting and keeping Palm Sunday."
The Archbishop of Canterbury, Theodore of Tarsus, traveled north to visit Oswy in 669 and made such an impression that Oswy was going to make a pilgrimage to Rome. He never made it, dying on 15 February 670. He was buried at Whitby, where his daughter the nun then resided.