St. Oswald was a 7th-century king of Northumbria, known for his role in spreading Christianity in England. He became king in 634 AD after the death of his predecessor, and he is often remembered for his efforts to unite various tribes under his rule. His reign was marked by military success and the establishment of monasteries, which helped to promote the Christian faith. Oswald is also recognized as a saint in both the Roman Catholic Church and the Anglican Communion. He was killed in battle in 642 AD, and his legacy includes the founding of the monastery at Lindisfarne, which became a center of learning and spirituality. His feast day is celebrated on August 5th.