Oswald was King of Northumbria from 634, until his death on August 5, 641/42, and is venerated as a saint, of whom there was a particular cult in the Middle Ages. He was the son of Æthelfrith of Bernicia and Acha of Deira, and came to rule after spending a period in exile. After defeating the Welsh Gwyneddian ruler Cadwallon ap Cadfan at the Battle of Heavenfield, he brought the two Northumbrian kingdoms of Bernicia and Deira once again under a single ruler, and promoted the spread of Christianity in Northumbria. Oswald was given a strongly positive assessment by the historian Bede, writing a little less than a century after Oswald’s death, who regarded Oswald as a saintly king. Bede is also the main source for present-day historical knowledge of Oswald. After eight years of rule, in which Oswald was the most powerful ruler in Britain, he was killed in the Battle of Maserfield while fighting the forces of Penda of Mercia, who then himself was defeated by Oswald’s brother Oswiu.
Not long after, Oswald came to be regarded as a saint. Bede says that the spot where Oswald died came to be associated with miracles, and people took dirt from the site, which led to a hole being dug as deep as a man’s height.