The Duke and Duchess of Sussex's son, Archie Mountbatten-Windsor, is now technically a prince - a title which Meghan controversially claimed was previously denied to him because of his race.
His younger sister, Lilibet "Lili" Mountbatten-Windsor, is also entitled to be a princess following the death of the Queen and with her grandfather, the Prince of Wales, becoming King.
The rules set out by King George V in 1917 mean Archie and Lili - as the children of a son of a sovereign - also now have an HRH style if they choose to use it.
In 2021, it was suggested Charles - in a bid to limit the number of key royals - intended, when he became monarch, to prevent Archie becoming a prince.
To do so, he will have to issue a Letters Patent amending Archie's right to be a prince and Lili's right to be a princess.
Until that potentially happens or if it does not, Archie and Lili remain a prince and princess, whether their parents choose to use the titles or not.