Oswald was born around AD 605, son of King Aethelfrith of Bernicia and his second wife, Princess Aacha of Deira. Aethelfrith had recently taken Deira from its King, Edwin. When Oswald was 11 he and his family fled Northumbria when Edwin and his East Anglian army re-took the kingdom.

Oswald took refuge with King Eochaid Buide at Dunadd. Oswald and his brother, Oswiu, were educated at the Abbey on Iona and were converted to Christianity. Aged around 23 Oswald went to Ireland with King Connad Cerr of Dalriada and fought against the Irish Cruithne at the Battle of Fid Eoin.

Meanwhile, back in Northumbria, King Edwin was at war with the combined forces of Gwynedd and Mercia. Oswald's half-brother, Eanfrith, took the throne after Edwin died in battle in AD 633, but was captured and killed after less than a year in power. Oswald's time had come.

Marching south with a small army Oswald encountered a large Welsh force led by Cadwallon (King of Gwynedd) at Heavenfield. Oswald raised a large cross and he and his soldiers prayed around it before the battle. Oswald was victorious and led his troops into York.

Initial attempts to convert Northumbria to Christianity were unsuccessful so Oswald sent to Iona for assistance. Bishop Aidan arrived the next year and set up his monastery on the island of Lindisfarne, near to the Royal Castle at Bamburgh. Aidan spoke only Gaelic and the King often travelled with him to act as an interpreter.

During a banquet at Bamburgh one Easter a group of beggars arrived at the castle. As the Royal retainers were about to throw the men out, Oswald took a silver dish piled with meat from his table and gave it to the starving beggars. This so impressed Bishop Aidan that he prayed that the hand which had done this might never decay.

Not content just with evangelising his own people Oswald convinced Cynegils, King of Wessex, to allow St. Birinus to preach there. In AD 638 Oswald began to expand his kingdom by both diplomatic means (marrying his brother, Oswiu, to Princess Rhiainfelt of North Rheged) and military. Eventually Oswald's rule covered Edinburgh and large parts of lowland Scotland.

In AD 642 King Penda of Mercia combined his forces with the armies of Gwynedd, Powys and Pengwern and marched against Oswald. The armies met in battle at Maserfield on August 5th. Again Oswald erected a cross and prayed for the lives of his men. Oswald's army again emerged victorious, but Oswald was killed. Maserfield is now called Oswestry (Oswald's Tree).

Oswald's head and arms were removed and placed on stakes until his brother and successor, Oswiu, removed them. (Although one story has it that Oswald's pet raven carried off one arm and dropped it by an ash tree where a holy well sprang up). Oswald's head was placed in the coffin of St Cuthbert on Lindisfarne and now resides in Durham Cathedral. The arms were originally taken to Bamburgh. One later went to Nostell Priory in West Yorkshire and the other (un-corrupted after Aidan's prayer) was stolen by the monks of Peterborough Abbey but was lost during the Reformation.