Who was rex guilelmus?

Rex Guilelmus, often referred to as William the Conqueror, was the first Norman King of England, reigning from 1066 until his death in 1087. He was originally Duke of Normandy and gained the English throne after defeating King Harold II at The Battle of Hastings in 1066. His reign marked significant changes in English society, governance, and culture, including the introduction of Norman feudalism and the commissioning of the Domesday Book. William's legacy is pivotal in shaping medieval England.