Britons; what are you expecting when Charles becomes King?

It’s okay to be Protestant, non-Anglican, so long as you “join in communion” with the C of E. The statute was drafted to ensure Lutheran George of Hanover could become king.

Did he stay Lutheran, or converted he to Anglican?

He remained Lutheran, and retained power over the Lutheran Church in Hanover, but he also worshipped in Anglican churches and was in good standing with the Anglican Church. The churches weren’t regarded as being sufficiently different to exclude him from the British throne, although it was still a source of criticism and dissatisfaction in Britain at the time.

In a way, it’s similar to the situation with the Presbyterian Church in Scotland. The British monarch must swear to uphold the Presbyterian Church as well as the Anglican Church – though he is not the head of the Presbyterian Church because it is not governed by a single head, but by a General Assembly.

And then when little King Whatzit the First of His Name kicks off from some childhood illness? Back to Queen Elizabeth (unless she’s had a male child already)?

Would the list of monarchs then go:

Queen Elizabeth II
King Whatzit I
Queen Elizbeth II … Or would she then be Queen Elizabeth III?

I’d recommend Princes at War: The Bitter Battle Inside Britain’s Royal Family in the Darkest Days of WWII by Deborah Cadbury as a good start.

Or if George VI’s wife died (ie if the Queen Mother died - but she obviously wasn’t known as that at the time), and he remarried and had a son. That son would have jumped ahead of his elder sisters in the line of succession. Not terribly likely, but definitely not beyond the bounds of improbability.

Pretty sure it’s only for titles that are passed down by gender as well as age.

Heirs for property and money are different. That just means they inherit stuff.

Which is exactly the scenario which triggered the Glorious Revolution and the ouster of King James II. By his first wife, he had two daughters, Mary and Anne, who were good Protestants. So even though James was Roman Catholic, the succession was set for Protestants.

Then his first wife died and he re-married to a Roman Catholic. Who then got pregnant. And the baby was a son. Who automatically became the heir apparent, bumping Mary and Anne down in the succession. And it was clear that James would raise his son as a Roman Catholic.

Took a while for all that to work out, but the net result was that James and his family fled England, and were repaced as monarchs by Mary and her husband William.

To be precise, she had two children who died in infancy. Then there was a gap of eleven years before the pregnancy that produced a baby boy, at a time of increasing fractiousness about James’s policy towards Catholics, and the arrival of large numbers of French Protestant refugees from Louis XIV’s repression. So the staunchly Protestant (including James’s daughter Anne) started/affected to believe the pregnancy wasn’t even real (or if real, that it was time to bring in the Protestant alternative of William and Mary, to ensure there couldn’t be a Catholic duccession).

When the baby was born the rumour was spread that he was a ringer, smuggled in in a warming-pan (hence the custom thereafter that a representative of Parliament had to be present at royal births, to ensure no hanky-panky - latterly, just to be in the building, until the practice was finally dropped).

Actually, there were a number high government officials and noble ladies present at the birth of James’ son, and James published their sworn testimony that the birth was genuine.

The rumours continued nevertheless…

I think she would still be Queen Elizabeth II (though the notion of her stepping down is, I think, totally wrong).

Vlad III (the Impaler, aka Dracula) was king three times, and history records him as Vlad III, not Vlad III, IV, and V. (It would have been even more confusing if some of his rivals had been named Vlad.)