Prince George has just 7 days left before he has to follow unique royal rule

Prince George is just days away from hitting a major milestone, which will also see him follow a strict royal rule that his own father, Prince William, also had to follow. The second in line to the throne will be turning 12 in seven days, on July 22.

George will then likely have to change his plans and arrangements when it comes to travelling with his family. While there are many protocols that ensure the safety and well-being of the Royal Family when they travel, there is one strict rule which aims to protect the line of succession. According to the rule, it is against royal protocol that two heirs to the throne travel together.

Since William is heir to the throne and George is next in line, it could likely mean that the rule will take effect sometime after next week.

The Prince of Wales had to go through the same when he turned 12 in 1994.

Former RAF Squadron Leader, Graham Laurie, who used to work for the royals, told Hello Magazine's A Right Royal Podcast: "Interestingly, we flew all four: the Prince [King Charles], the Princess [Princess Diana], Prince William and Prince Harry, up until Prince William was 12 years old.

"After that, he had to have a separate aircraft and we could only fly all four together when they were young with the written permission of Her Majesty.

"When William became 12, he would fly normally in a 125 from Northolt and we would fly the 146 out with the other three on."

It is not clear whether George will be the one travelling solo or William.

Other peculiar travel rules for members of the Firm include not eating certain foods to avoid any case of poisoning.

The royals, particularly the monarch and the Prince of Wales, also travel with bags of their blood type in case of an emergency, as well as their own doctor.

Lastly, another essential item the royals usually travel with while abroad is a black outfit as a precautionary measure for the purposes of mourning.