William the Conqueror was a powerful leader from Normandy in France who became the first Norman King of England in 1066. He is best known for winning the Battle of Hastings, where he defeated King Harold II and claimed the English throne. This victory changed the course of English history and led to the introduction of Norman culture and language. After becoming king, William worked to strengthen his rule by building castles and establishing a new system of governance. He ordered the creation of the Domesday Book, a detailed survey of his new kingdom, which helped him manage land and resources effectively.