'One story says his arm was rescued by his pet raven and then dropped, and a holy well sprang up.'

Andrew Chapman looks at the life of a saint who was also a king.

To become venerated as a saint having been the son of a pagan by the name of Aethelfrith the Ravager is perhaps impressive in itself. Aethelfrith was king of Bernicia in Northumbria and died in battle at the hand of Redwald, king of the East Angles, when his son was only 11 (Oswald was born around the year 604).

Oswald fled with his mother Acha and his brothers (including one who later became Saint Ebbe the Elder), taking refuge at Dunadd in Scotland. There Oswald was educated by the monks of Iona, who converted him to Christianity. The neighbouring kingdom of Deira had meanwhile passed to Acha's brother Edwin, who was hostile to Oswald's family and dominated Bernicia as well. Oswald trained as a soldier as well as a cleric, and fought in a battle of 628.

When Edwin died in 633, his cousin Osric took Bernicia, and Oswald's brother Eanfrid took Deira - the kingdoms continued to fight and paganism persisted. They were both killed in 634, however - Eanfrid at the hand of Cadwallon, the king of the Britons of Gwynedd. At this point Oswald raised his own army and returned to fight Cadwallon at Heavenfield, near Hadrian's Wall at Hexham.

There Oswald had a vision of St Columba, and he erected a large cross and asked his army to pray with him. The battle went their way and Cadwallon was killed. Bede, who wrote extensively of Oswald less than a century later, says it was this victory that enabled Oswald to unite Northumbria - and even that it "brought under his dominion all the nations and provinces of Britain", though this seems exaggerated.

Oswald then brought the Irish bishop Saint Aidan to the area, who established himself at Lindisfarne, and between them (with Oswald translating to Irish for Aidan) they established church and monastic life across the region. Oswald also married the daughter of the king of Wessex and influenced evangelism there too.

Bede writes that Oswald's rule was generous and charity to the poor renowned. He was described by a contemporary as having "eyes bright blue, hair yellow, face long and beard thin, his small lips wearing a kindly smile". He was not without enemies, though - although he dominated the north, Mercia and East Anglia were under the away of the pagan Mercian king Penda, who eventually engaged with him in battle somewhere near Oswestry in 642 on 5 August.

Penda was victorious and cruelly mutilated Oswald's body - Oswald, seeing his defeat, had prayed for himself and his army beforehand. His bones were left on stakes there (hence perhaps the name Oswestry - Oswald's tree) for a whole year, though one story says his arm was rescued by his pet raven and then dropped, and a holy well sprang up.

Eventually Oswald's remains were taken away, and ended up at various times in Gloucester, Peterborough and Lindisfarne. His head is believed to be with the remains of St Cuthbert at Durham - though four other heads of Oswald are claimed across Europe! St Aaidan had once said, when seeing Oswald's generosity, "may this hand never perish" - and the same arm is said to remain uncorrupted either at Bamburgh or Peterborough. Many tales of healing are associated with his remains and the cross at Heavenfield.

Oswald's memorial day is 5 August, and he is patron of Zug in Switzerland.

Other 'O' saints:

Odo (c878-942) was the second abbot of Cluny in France, where he reformed the monastic system. His feast is 18 November and he is the patron saint of rain!

Odile (c662-720) was the blind daughter of the Duke of Alsace. Her sight was miraculously restored and she founded abbeys. When she died her sisters' prayers are said to have restored her to life, but she told them of the happy afterlife and died again. She is patron of Alsace and eye disease and is remembered on 13 December.

• Andrew Chapman

• Other Saints in the series

Find out more about the saints:
• Catholic Forum
• Catholic Encyclopaedia