Oswald was the King of Northumbria and son of AEthelfrith who was killed by Penda at Maserfield.
Oswiu was his brother
Osric of Deira was the King of Deira, and nephew of Edwin, who was killed by Cadwallon.
and Oswine was the son of Osric…
So to recap… Oswald and Oswiu are brothers and Bernician. Osric and Oswine are father and son, and are Deiran.
Isn’t this fun?