Oswin was cousin of St. Oswald and also was a king in Northumbria. Due to treachery, his was only a short reign.
According to St. Bede he was greatly loved and ruled his province most successfully. According to St. Aidan he was a man of handsome appearance and great stature; pleasant in speech and courageous in manner.
He was deeply involved in tribal warfare. Ultimately, realising that he was outnumbered, he disbanded his army and he himself took refuge in the house of a friend. He was betrayed and killed on 20th August 651. He is regarded as a martyr, though not in the strict sense of the term. He is buried at Tynemouth priory.