Guilielmus, often referred to as William, is a name of Latin origin meaning "resolute protector." It has been widely used in various cultures and languages, often associated with historical figures and royalty. Notably, William the Conqueror was a significant figure in history, known for his role in the Norman Conquest of England in 1066. The name has evolved into various forms, such as Guillaume in French and Guglielmo in Italian. It remains popular today, often shortened to Will or Bill. Many notable individuals, including writers and leaders, have carried the name, contributing to its enduring legacy.