In 1066, William invaded England with a large army, claiming the throne of England for himself. He defeated King Harold II at the Battle of Hastings on 14 October 1066, and was crowned King of England on Christmas Day 1066. William's conquest of England was a significant event in European history, as it marked the beginning of the Norman era in England and the end of Anglo-Saxon rule.
William was a powerful and effective king, and he made many changes to English society and government. He introduced the feudal system to England, which was a system of land tenure and military service. He also built many castles and fortifications throughout England, in order to maintain control over the country. William was a ruthless ruler, and he was not afraid to use violence to suppress any opposition to his authority.
William's reign lasted for 21 years, and he died in 1087 at the age of 60. He was succeeded by his son, William Rufus.