King Oswald was a 7th-century ruler of the Kingdom of Northumbria in what is now northern England. He is best known for his efforts to spread Christianity in his kingdom, which was a significant part of his reign from 634 to 642 AD. Oswald was a devout Christian and played a crucial role in establishing the Church of England. Oswald's reign was marked by military success and the unification of various tribes under his leadership. He is often remembered for his battle against the Kingdom of Mercia at the Battle of Heavenfield, where he achieved a decisive victory. His legacy includes the promotion of peace and the growth of Christianity in the region.