Athelstan was a 10th-century king of England, known for being the first king to rule over all of England. He was the grandson of Alfred the Great and played a key role in unifying the various Anglo-Saxon kingdoms. Athelstan is also remembered for his military successes, including victories over the Vikings and the Scots. He is considered an important figure in English history for his efforts in establishing a unified kingdom and for his contributions to the development of English law and government.