When a relative of the Queen was last born in the United States, in 2013, very little fuss was made.
She was Maud Windsor, first daughter of Lord Frederick Windsor and his wife, the actress, Sophie Winkleman.
Maud Windsor is a distant 51st in line to the throne and will slip down another couple of notches when both the Duchess of Sussex and Zara Tindall give birth this year. (Freddy Windsor, by the way, is son of Prince Michael of Kent - the Queen’s cousin and, like her, a grandchild of King George V).
Meghan and Harry’s new arrival will be the Queen’s tenth or eleventh great-grandchild (we don’t know about either Meghan or Zara’s due dates) and this boy or girl will most likely be born in California.
So baby Sussex number two will be both US citizen, because of its place of birth, and a UK citizen because of Harry.
But he or she will be eighth in line to the British Crown – therefore much closer to the top of the tree than Maud.
So it will further tie the Sussexes to the British Royal Family - despite their high profile departure from it - and it goes some way to explain why this pregnancy announcement received such huge publicity.
I even had a breaking news alert on my phone from the Guardian last night, which, given its usual agnostic approach to royal news, came as a surprise.
In the US, it was treated as a major breaking story on some of the news networks and given the kind of attention that other Californian-based celebrities simply wouldn’t get.
Celebrities are very common in America but celebrities with a royal blood-line are not.
It’s a rare combination and the kind of money-can’t-buy stardom that will serve Harry and Meghan well.
Despite Harry’s on-going difficulties in his fraternal relationship with Prince William and his now strained relationship with his father, people might be surprised to learn that he remains very close to the Queen.
By all accounts, he still speaks to her often and, in turn, she still has a lot of time for her grandson, despite the geographical distance which now exists between them.
That doesn’t mean Harry will return to his former royal role – he and Meghan have now set out on their new path together – and they do so as a happy and growing family.
But they are now an American family, with significant Netflix and Spotify deals and the financial independence they sought.
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Archie might have been born in the UK to great fanfare (and a fair bit of controversy about how Harry and Meghan chose to announce it) but he has spent more of his life in North America than Britain.
And it is in America that his parents will be able to choose how they announce their next child’s arrival into the world.
Harry and Meghan left the Royal Family to gain control of their lives and of their privacy.
They didn’t leave to escape the media but to escape the media dictating its terms to them.
And following Meghan’s significant legal victory over the Mail on Sunday last week in her privacy battle, the Sussexes have shown that they are now in control of their lives in a way in which they simply were not before.