Cher, Madonna and Prince William?

What do Cher, Madonna and Prince William have in common?
Unless Prince William has hidden song and dance skills, the only thing which could be said about all three of them is that they don't use a surname (last name). Now everyone knows that Madonna's surname is actually Ciccone, and a few people may know that Cher's surname was (before it was legally dropped) Sarkisian LaPiere, but what is William's surname? Surely he must have one... mustn't he?
I asked my British born husband for clarification and was surprised that he looked perplexed. I assumed this would be an easy answer for a person who'd spent many a year in a COE school and thinks that Liz is the "most beautiful woman in the world", but he did have to do a bit of thinking. His final answer was one I thought was a cop out, but is actually true - Royals don't have legal surnames.   "But what about William and Harry when they are serving in the military?  They can't be called Lieutenant Prince William, can they!?"  Either unsure or not up for a complex explaination to an ignorant American, he told me to look it up.  So I did, and here's the low down:

Prior to 1917 surnames, when rarely used, were those of the father's house or dynasty, so for this reason Queen Victoria's eldest son Edward VII belonged to the House of Saxe-Coburg-Gotha (the family name of his father Prince Albert). Edward VII's son George V became the second king of that dynasty when he succeeded to the throne in 1910.   In 1917, George V, in response to the the anti-German sentiment of many British people during this time declared the official British Royal Family's surname to be Windsor. 

Fast forward to 1960 ...  Queen Elizabeth and Prince Phillip decided that they wanted their direct decendants to be futher distinguished and through an Order-in-Council designated Mountbatten-Windsor as the personal surname of their decendants. To further complicate the matter, according to the Wikipedia entry,  "the only people who would officially hold the surname under the Order-in-Council would be any male-line great-grandchildren of the Queen in cadet branches; i.e., the children of any sons of the Duke of York and Earl of Wessex. Similarly, in the event that any male-line granddaughter of the Queen were to have a child whilst unwed, such a child might have the surname of Mountbatten-Windsor. The surname applies to any male-line descendants of The Queen and Prince Philip who do not hold the style of Royal Highness and rank of Prince/Princess of the UK."

Apparently, William and Harry (whos legal names are Prince William of Wales and Prince Henry of Wales) have at some point used the Mountbatten-Windsor surname, but it appears they too find this a bit confusing (or perhaps pretentious?) and both Princes reportedly used Wales as their surnames and were referred to as Officer Cadet Wales during their time at Sandhurst.  Princess Eugenie of York and Princess Beatrice of York (Sarah "Fergie" Ferguson's* daughters) have also chosen this option and use York as their surnames.

Phew!  Now don't say I never taught you anything.


*Don't let Fergie's surname confuse you - she is a Ferguson because she married into the family.  Same with Diana, who's legal name was Diana Spencer.  You don't get to take the Windsor/Mountbatten-Windsor/York/Wales surname with you after divorce.