Archie and Lilibet Mountbatten-Windsor
The absence of any royal titles for Archie and Lilibet is particularly unusual, as they’re children of Prince Harry and Meghan Markle, the Duke and Duchess of Sussex.
As his father is a Duke, Archie may have been eligible to hold one of Harry’s subsidiary titles such as the Earl of Dumbarton.
But Archie is simply known as Master Archie Harrison Mountbatten-Windsor, and his younger sister Lilibet also carries the Royal Family’s surname rather than a title.
Under the George V convention, Archie Harrison and Lilibet Diana Mountbatten-Windsor were not eligible for Prince and Princess titles at birth as the monarch’s great-grandchildren.
However, during the reign of Prince Charles, Archie and Lilibet will be grandchildren of the monarch through the male line, and therefore would arguably be eligible for Prince or Princess titles.