Little Archie Harrison Mountbatten-Windsor is seventh in line to the British throne, which certainly makes him royal, but does it make him a prince?

The answer is complicated, but no, he's not.

Why not, his dad's a prince?

It all comes down to a decree issued by one of Archie's ancestors, King George V, in 1917.

According to Time magazine, this decree states that the British sovereign's children and their grandchildren (in the male line) are automatically granted the title of prince or princess. That's why Queen Elizabeth's grandson Harry is a prince.

When it comes to the sovereign's great-grandchildren, however, King George V declared that only the oldest son of the Prince of Wales’s 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 first-born son.

OK, but how come Archie's cousins Princess Charlotte and Prince Louis have royal titles?

In 2012, Queen Elizabeth issued a decree granting the title of prince or princess to all of Prince William's children. Hence Princess Charlotte and Prince Louis.

So, Archie is just plain old Archie?

The BBC explains that, as the eldest son of a duke, "Archie could have become Earl of Dumbarton — one of Harry's subsidiary titles — or have been Lord Archie Mountbatten-Windsor".

However, judging by the way Archie's name was announced on Instagram, it seems his parents have chosen not to use such courtesy titles at present, so he's just regular Master Mountbatten-Windsor.

That said, the AFP reports that the little royal could one day become a prince if his grandfather, Prince Charles, becomes king — all thanks to that decree made by his ancestor King George V a century ago.

We told you it was complicated!