Though Prince Harry and Meghan Markle's children Archie, 3, and Lilibet, 1, were born without titles, this has changed now that their great-grandmother the Queen has sadly passed.
Queen Elizabeth II's grandfather, King George V, set protocols which mean that both children and grandchildren of the British monarch are automatically entitled to use the titles of "Prince" or "Princess," and are also entitled to the "HRH"—His or Her Royal Highness—designation (as in "HRH Prince William").
Following the death of his mother, her eldest son automatically became King Charles III, making Archie and Lilibet grandchildren of the monarch. That means that they're entitled to go by Prince Archie and Princess Lilibet, and to use the HRH designation, as reported by The Guardian.
Whether or not the Duke and Duchess of Sussex will choose to call their children by these new royal titles in official communications is another matter, Hello! points out.
When Archie was born, it was suggested that he take the title of Earl of Dumbarton, but his parents reportedly refused because of the word "dumb" included in the name.
King Charles could decide to revoke Archie and Lili's claim to these royal titles, which he could do under his plans for a "slimmed-down monarchy," but he would have to do so via an official Letters Patent, according to The Guardian.
Although Prince Harry and Meghan Markle have retained their HRH titles since they renounced their royal duties in 2020, they are barred from actively using them, according to People. This is another reason it's plausible that Charles would prefer Archie and Lili not use their own HRH titles, but this too remains to be seen.
