When it comes to the sovereign’s great-grandchildren, however, King George V declared that only the oldest son of the Prince of Wales’ eldest son would be given a grand royal title.  

So, in terms of this rule, the only one of Queen Elizabeth’s great-grandchildren who qualifies is Prince George, Prince William’s firstborn son and Prince Charles’ oldest grandson.

However, in 2012 Queen Elizabeth issued a decree granting the title of prince or princess to all of Prince William’s children. That’s why his other children, Princess Charlotte and Prince Louis, have royal titles.

Told you it was complicated!

2. THEY’LL BE IN LINE TO INHERIT THE THRONE

They baby might not automatically qualify for a royal title, but it does qualify for a spot in the succession. They’ll be 11th in line to inherit the crown from Queen Elizabeth.

Here’s the pecking order:

1. Prince Charles (Queen Elizabeth’s eldest son)
2. Prince William (Prince Charles’ eldest son)
3. Prince George (Prince William’s eldest son)
4. Princess Charlotte (Prince William’s daughter)
5. Prince Louis (Prince William’s youngest son)
6. Prince Harry (Prince Charles’ youngest son)
7. Archie Mountbatten-Windsor (Prince Harry’s son)
8. Prince Andrew (Queen Elizabeth’s second son)
9. Princess Beatrice (Prince Andrew’s eldest child)
10. Princess Eugenie (Prince Andrew’s youngest child)
11. Princess Eugenie’s baby

3. THEY’RE NOT THE ONLY BRITISH ROYAL BABY WHO’LL BE BORN IN 2021

Princess Eugenie’s first cousin, Zara Tindall, is also expecting. The baby will be Tindall’s third child with former English rugby player Mike Tindall.