Whats the story behind Prince Williams name? Here's a look at its meaning, origin, and who picked it for him. Some of this is from the book The New American Dictionary of Baby Names, Penguin Books 1985.
Arthur- The name Charles originally wanted for his fist sons name. "Of uncertain origin: posibly Celtic artos 'bear.' Since the first Arthur mentioned in the records is Irish, the origin may be Irish art, stone. One of the most used first names in the English speaking world until the 1920s, but though still in regular use, now a minor name."
Philip-
Philip was given to Williams name after his grandfather, Prince Philip. "Greek Philippos 'fond of horses.' Biblical, N.T. Matt. 10:3, the name of one of the Apostles. In common use amongst the early Christians. Its use in medieval times is reflected in the commonness of surnames such as Philips, Philips, Phipps, etc. From the 16th century onwards one of the more densely used male names in Britian, but faded into the background to some extent throughout the 19th c."'
Louis-
A name that comes from Williams side of the family.... "French form of an Old German name Hlutwig 'famous in battle.' Modern German, Ludwig. Borne by the Frankish kings who ruled over kingdoms in Gaul and Germany from AD 500. Became extremely popular in the U.S. by the 1870s, and remained one of the top thirty names until the late 1920s. Subsequently faded."
Windsor-
A famous last name of British royal families.... "Common English place name, originally indicating a 'riverbank with a winch', used to pull boats from the water. The name took on especial significance when King George V made it the surname of the British royal family during World War One."