Thanks. I can imagine a scenario with a dying monarch and someone desperately trying to induce labor, so the baby is born before the death.
I think you mean:
Yes, and as the heir (period, not heir presumptive) of the King, she becomes the Queen.
I don’t know British law on this, but many monarchies have regencies while waiting to see if an heir presumptive is displaced by a pending birth.
examples, please.
Britain used to be a “sons first, daughter if there’s no other heir” type of monarchy, but at some point they changed to first born child.
I don’t have any easy cites, but a Google search of “posthumous heir” yields:
On June 20, 1837, the wording of Queen Victoria’s accession proclamation had a curious abnormality, courtesy of section two of the Regency Act,
“…the Imperial Crown of the United Kingdom of Great Britain and Ireland is solely and rightfully come to the high and mighty Princess Alexandrina Victoria, saving the rights of any issue of his late Majesty King William IV, which may be born of his late Majesty’s consort…”
In plain English, this means that according to the Act of Parliament, Victoria could be Queen on a temporary basis. Upon the birth of William IV’s hypothetical child, the child would immediately succeed to the throne as Queen Victoria’s heir.
Quite recently in fact - 2011. Of course, it won’t have any effect for quite some time, given that William’s first born is a boy anyway.
I believe it does not apply to people born before the change, either. So if for example Charles and all of his descendants were to die before the Queen does, the next in line would not be Anne (the second-oldest child), but Andrew (the second-oldest male child). 
i remembered the regent possibility from the race for an heir that happened pre-victoria. this would have kicked in if queen elizabeth was pregnant when her husband died. a male child would supersede princess elizabeth at that time.
So this seems to say I was kinda-sorta on the right track, but not quite.
Does this mean that nobody is ever a just-plain-heir(ess)? There are heirs presumptive and heirs apparent, but either way they progress from that status directly to Monarch without a pause as “heir” en route?
ISTM the word “heir” is used sometimes to refer to someone who receives an inheritance, even after they have received it. The Wiki page for Sarah Winchester, for example, says:
seemingly referring to the Widow Winchester as an heiress even after she inherited. I think it’s used this way a lot for heirs to a fortune. Is that usage also applicable to heirs to a throne?
And let’s see if I can apply these lessons in Royal Heir Nomenclature in a practical American scenario:
The term “heir apparent” is commonly used, figuratively, to refer to someone who seems likely to become the next president – often the incumbent Vice President. In today’s WaPo, for example, we see this discussion:
But that seems wrong now. Isn’t “heir presumptive” the better phrase, since there could always emerge someone else even more likely to “inherit” the office?
ETA: For reference, here’s the WaPo Op-ed cited:
I think the idea is that the VP of an incumbent president who chooses not to or cannot run is always the default frontrunner. As such without Harris dying or resigning there cannot be anyone who can jump the gun until 2024.
How many Americans not reading this thread know the difference? Everybody has heard of an heir apparent. Bloody nobody has heard of an heir presumptive.
Not so sure of that. I think the phrase “heir presumptive” is seen often enough that many Americans have seen or heard it. But as this thread has shown, few of us know what it means. Now, at least, the ignorance of some of us Dopers is fought. A Straight Dope Success story!
The question was asked of government lawyers, and their consensus was that the succession could not be delayed, but the baby would nevertheless become king immediately on birth, so there would be a new queen for a short period who would then be replaced at the moment her brother was born. There was explicit legislation providing for this to happen after the reign of William IV, but the lawyers believed that the legislation merely restated a general principle.
They were also asked to dispel a theory that was floating around that an older sister had no seniority over a younger sister, so Elizabeth and Margaret actually had an equal claim to the throne. Which would mean either that they would become joint queens or that the Crown would go into abeyance until someone (who???) decided which one should get the job. The latter is how it works for some peerages.
Something I don’t think has been mentioned in this thread is that Catholics are still specifically excluded from the succession.
Only someone who belongs to the Church of England, and promises to preserve the Church of England and the Church of Scotland, and uphold the Protestant succession, can succeed to the throne.
So if Prince Charles suddenly decided to become a Catholic, he would no longer be the heir to the throne.
Only Catholic? What about any other Protestant Church, non-Christian religion or atheism? Would any confession for a different belief or non-belief exclude him from becoming king?
The monarch is supreme governor of the Church of England, so I can imagine some problems arising if Charles were to convert to Hinduism or the like.
Catholics are mentioned specifically, but other religions (and atheism) are implied, because the monarch must be ‘in communion with the Church of England’. That is, he/she must be a member in good standing of the Church of England.
It’s a fairly strange situation, but since the time of Henry VIII, the monarch has been the head of the Church of the England. So it would be a major anomaly for the monarch not to be Anglican.
This actually happened for a few years in the reign of the Catholic James II, and was one of the reasons that he was kicked out as king. Catholics were later specifically excluded by the Act of Settlement (1701), and the succession was made Protestant only.