Guillaume, also known as William, is a common name of French origin. It is derived from the Germanic name Willahelm, which means "resolute protector." The name has been popular in various cultures and languages, often appearing in different forms, such as Guillermo in Spanish and Wilhelm in German. One of the most famous historical figures named Guillaume is William the Conqueror, who became the first Norman King of England in 1066. His victory at the Battle of Hastings marked a significant turning point in English history, leading to the Norman conquest and the establishment of a new ruling class in England.