The loved-up pair will leave their Royal Wedding at Windsor Castle on Saturday with fancy new names as a gift from the Queen.
Her Maj will bestow a new title to her grandson on the morning of his big day – as she did with Prince William and Kate Middleton.
The title will be made official at the wedding, and automatically adopted by Meghan as she turns from “commoner” to “royal”.
That Dukedom – the highest title in British peerage – will most likely see Prince Harry become the Duke of Sussex, like when Wills became Duke of Cambridge.
Hot toff Millie poses in a barely-there swimsuit
Harry will then become “His Royal Highness the Duke of Sussex” while his new wife becomes the female equivalent.
So the moment Meghan and Harry say “I do” she will go from “Rachel Meghan Markle” – her full name – to “Her Royal Highness the Duchess of Sussex” or “Meghan, Duchess of Sussex”.
Should Harry turn the title down, or the Queen decide not to bestow the new title on him, Harry would remain “HRH Prince Henry of Wales”.
Meanwhile Meghan would become “Her Royal Highness Princess Henry of Wales” – making her a Princess.
But she won’t be called “Princess Meghan” alone – as only those born into the Royal Family are bestowed the privilege of having Princess at the start of their name.
Racy royal Kitty Spencer squeezes her cleavage into a bulging bikini
The reason for Her Maj bestowing the Duke of Sussex title on Harry may be down to the similarities he has with the previous person who held that title.
That person was Augustus Frederick, who lived at Kensington Palace and married for love, rather than choosing brides who fitted the traditional royal mould.
Frederick was not given consent by his father, King George III, to marry his first wife Lady Augusta Murray, as she was considered to be from too low a social rank.
Yet the Prince married her anyway, in secret in Rome in 1793, and then again in England when they returned.