Prince Harry and Meghan Markle’s first baby finally arrived when the duchess gave birth to a healthy boy on Monday. Now the guessing game begins as to what his name, as well as his title, might be. But one thing’s for sure — according to experts, he won’t be called a prince just yet.

As expected by fans, Prince Harry and Meghan kept up with modern times and announced the birth of their firstborn on social media. “We are pleased to announce that Their Royal Highnesses The Duke and Duchess of Sussex welcomed their firstborn child in the early morning on May 6th, 2019,” the royal couple posted using their recently minted Instagram account.

The post also gave a few details about Baby Sussex but did not yet include the child’s name. “Their Royal Highnesses' son weighs 7lbs. 3oz. The Duchess and baby are both healthy and well, and the couple thanks members of the public for their shared excitement and support during this very special time in their lives,” the post continued.

While the royal couple has not yet announced the name of the baby, long-time royal observers are already speculating on what his royal title could be. Chances are he’s going to be called the Earl of Dumbarton.

Earl of Dumbarton was a title that Prince Harry received from his grandmother, Queen Elizabeth II, last year. A duke’s first son is “permitted to use one of his father’s lesser titles,” so there’s a good chance that Baby Sussex will be granted that title.

On that note, there is also a possibility that Meghan’s son will be called the Baron Kilkeel. This is Prince Harry’s subsidiary title given to him by the Queen last year.

Of course, other fans are wondering why the newborn can’t be simply referred to as a prince or an HRH like his father, Prince Harry. Apparently, there is a strict rule as to who can be named prince or princess.

Basically, the reason why the newborn can’t be called prince yet is that he is only the great-grandson of the current monarch, Queen Elizabeth II. “Baby Sussex is too distant a relation to the current monarch to automatically be HRH Prince Firstname of Sussex,” explained Selene Daws on Quora.

“…The title [of prince] was limited to the children of the monarch, male-line heirs of the Prince of Wales, and male heirs of the oldest son of the Prince of Wales,” another Quora user, Eileen Wood, explained. “Just before Prince George's birth, Queen Elizabeth expanded that to ANY child of the oldest child of the Prince of Wales, regardless of gender.”

Thus, there are two ways Prince Harry and Meghan’s son can become a prince. The first possibility is when his great-grandmother will grant him the title. The second possibility is when his grandfather, Prince Charles, will eventually become king and he gets an automatic upgrade. For now, however, he’ll likely be called Earl of Dumbarton or Baron Kilkeel.

Meghan Markle and Prince Harry Prince Harry, Duke of Sussex, and Meghan, Duchess of Sussex, attend the Commonwealth Day service at Westminster Abbey on March 11, 2019, in London, England. Samir Hussein/Samir Hussein/WireImage