So how is it that Kate isn't actually a Princess?

No, they were maligned because they were unmitigated evil, even by the standards of British treatment of the Irish.

prior to marriage she was: lady diana spencer. her father was THE earl spencer, she was lady due to being his daughter.

after she was married she wasn’t refered to as lady di, but princess di(ana).

  1. Princess in Your Own Right:
    a. Be born the daughter of a monarch
    b. Be born the daughter of a monarch’s son. (Note this is not necessarily the incumbent monarch: the Queen’s cousin Princess Alexandra is still alive and kicking, AFAIK; she was the daughter of one of George V’s sons, and retains her title.)
  2. Marry a Prince, who would be one of:
    a. A monarch’s son
    b. A monarch’s son’s son
    c. The eldest son of the eldest son of the Prince of Wales (If William and Kate have a son before the Queen passes on, he would automatically become a prince; this was the case as well from 1894-1901, when the future Duke of Windsor was the eldest son of the Duke of York (the future George V), who was in turn the oldest living son of the Prince of Wales (the future Edward VII)
    d. A person who was styled ‘Prince’ by special creation by letters patent from the Queen (In the 59 years of her reign, she did this once, and that was for her husband, so count it unlikely.)
  3. Get the Queen to create you a Princess by letters patent. (Helpful hint: get the Prime Minister to ‘advise’ her to do so.)
  4. Marry a foreign prince but do not rfenounce your British citizenship. Ask the Queen to receive you formally as Princess ___ of ___.

It’s rather interesting that the present Prince of Wales and Princess Royal were not Prince and Princess at birth, being the children of the king’s daughter, even though they were at the time second and third in line for the throne. George VI speedily remedied this by the letters patent route.

(I’m indebted to Lord Feldon’s post #9 for some of the detail work in this.)

The hypothetical younger and female children of William, if and when, are Lord/Lady Firstname Mountbatten-Windsor, but how is it they would get “promoted” on the accession to the throne first of Charles (their grandfather) and then of William? Or can you become a prince(ss) when your grandparent becomes the sovereign? I thought you had to be born as the grandchild of the monarch.

ETA: I can see that this scenario has been very rare, since few if any monarchs have reigned as long as Elizabeth II.

The letters patent don’t say anything about being born as a grandchild. They say that “the children of any Sovereign of these Realms, and the children of the sons of any such Sovereign, and the eldest living son of the eldest son of the Prince of Wales shall have and at all times hold and enjoy the style, title, or attribute of Royal Highness with their titular dignity of Prince or Princess prefixed to their respective Christian names or with their other titles of honour.” Upon Charles’ accession, they’d turn into children of a son of a Sovereign.

I’m not sure it’s ever happened before. The whole thing was only hard-coded into letters patent during the reign of Queen Victoria. The children of George V came closest to having their status changed by the accession of a grandparent, but Queen Victoria did that herself three years before her death. (They were born as His/Her Highness, and she upgraded them all to His/Her Royal Highness. At the time, male-line great-grandchildren were all HH. George V took that away from them (even the ones already living) with the above-quoted letters patent.)

I think the whole “Princess William” thing is goofy. Makes her sound like a transvestite, and hearkens back to the bad old theory of wives as chattel. If I were the British monarch, I’d issue letters patent that henceforth all wives of British princes are to be known as “Princess [Female first name],” either that given at birth, or chosen by the woman at marriage.

Better yet, why not give them the same thing that a common man who marries a princess gets automatically, that is, nothing at all.

And while we’re at it, can’t we call them “patent letters”? I still don’t know what it means, but adjectives come before the things they modify in this language, dammit.

… said the governor-general to the heir apparent …

Shut up with your Frog terms.

I was in error here. When the Queen (then Princess Elizabeth) was eight months pregnant with what turned out to be Prince Charles, it belatedly dawned on somebody that the child, though second in line for the throne from birth, would actually not be a prince or princess according to George V’s letters patent (see post #9). So George VI by his own letters patent made any children of Princess Elizabeth HRHs and princes or princesses of his realms. Charles and Anne were in fact prince and princess respectively from birth – but it was a close thing.

…by a date certain, on advice of the attorney general…

… as the notaries public affirmed, in many deeds poll …

… as duly acknowledged by the Lords Spiritual and the Lords Temporal…

it isn’t any different than using mrs john doe. jane roe marries john doe; if she keeps her name she is ms jane roe, if she takes his name she is mrs john doe. she married prince william of wales, that makes her princess william of wales.

the queen gave william his own title “duke of cambridge” so now her stationary will read “hrh the duchess of cambridge” no first names at all.

But the Lords Spiritual do not include Bishops Suffragan or Bishops Coadjutor!

More like the outmoded custom of married women being referred to Mrs HisFirstName HisLastName.

If you want to get egalitarian about it, marrying someone shouldn’t change your status at all. She’d remain plain Ms. Kate Middleton. But we’re talking about a system based on inequality. Seems only fair that she’d have to play by the traditional rules. Princess William, it is. Or, more often, the Duchess of Cambridge. Doesn’t look to me like she has anything to complain about.

Google gives about 1,500,000 hits for “Princess Kate” (inside quotes so it only gets that as a phrase). So I suspect that in the popular mind she will be that, just as we had “Princess Di”, even though it’s technically incorrect.

It’s odd; I don’t remember ANY reference to a “Princess Charles” at the time, none at all, not even by royalty-mad pedants. The phrase “Princess Diana” was all over the place, and don’t remember anyone ever saying it was wrong until after the divorce.