In 616 Aethelfrith the pagan King of Northumbria sent his son Oswald to Scotland to the monastic settlement founded by Columba in the late 500's on the island of Iona for protection.. Oswald encountered the Christian faith converted and was baptised.
In 628 Oswald returned from exile to claim the throne. He met Cadwallon in battle near Hexham. Oswald won a victory "as complete as it was unlikely," defeating and slaying Cadwallon (the victor, as the Welsh bards tell us, of forty battles and sixty single combats). The battle site was thereafter known as Heavensfield.
Northumbria, now united, became the most powerful of the Seven Kingdoms, and Oswald was recognized as paramount king of the Heptarchy.
Out of concern for the his people he sent messengers to Iona asking for a Christian priest. The first to come was a tactless failure. His replacement, Aidan, was an outstanding success. Oswald, who was fully bilingual, would stand beside Adian as he preached and would interpret his sermons. Aidan was soon joined by other missionaries establishing Lindisfarne mission resulting in the flourishing of the Church in Northumbria.
In 642 Oswald was killed in a great battle near Maserfeld. As he fell dying, Oswald prayed aloud for the souls of his bodyguards, who died with him, and for the salvation of the people of Northumbria, and for his slayers.