The name William has Germanic origins and can be traced back to the Old Germanic language. It is derived from the elements "wil" meaning "will" or "desire" and "helm" meaning "helmet" or "protection." Together, these elements form the compound name "Willahelm" or "Willihelm," which translates to "resolute protector" or "strong-willed warrior."

The name gained widespread popularity in the Middle Ages, particularly after the Norman Conquest of England in 1066. William the Conqueror, the first Norman king of England, played a significant role in popularizing the name throughout the British Isles. His birth name was Guillaume, the French form of William, but it became anglicized after his conquest.

One of the earliest recorded instances of the name can be found in the Old English poem "Beowulf," where the character Wiglaf is described as a faithful warrior and companion to the hero Beowulf. This early reference suggests that the name was in use among the Anglo-Saxons before the Norman Conquest.

The name William has been borne by numerous notable figures throughout history, including several kings and rulers. Among them are William the Conqueror (c. 1028-1087), the first Norman king of England; William Wallace (c. 1270-1305), the Scottish patriot and leader of the Wars of Scottish Independence; William Shakespeare (1564-1616), the renowned English playwright and poet; William the Silent (1533-1584), the main leader of the Dutch Revolt against Spanish rule; and William Wilberforce (1759-1833), the English politician and philanthropist who led the movement to abolish the slave trade in the British Empire.

These are just a few examples of the many influential individuals who have carried the name William throughout history. The name has endured for centuries and continues to be a popular choice in various cultures and regions around the world.