When it comes to the royal family, some rules only apply to certain members of the family, like the one that makes sure you always see Queen Elizabeth wearing gloves. Some only apply when the royals are out in public, but not while in private. Others are broken on occasion, but overall royal protocol is strictly followed—like these etiquette rules everyone in the royal family must follow. But there is one rule that Prince William and Kate Middleton have been breaking for a while now.
You’ll observe this rule-breaking every time you see them arrive in a new country; the family travels together. A royal family tenet generally prevents so many heirs to the throne travelling together in case of an accident or crash. The rule has a similar rationale to the United States’ “designated survivor” rule, which places a Presidential Cabinet member in a safe location away from the location of the State of the Union, in case a catastrophe occurs which wipes out the bulk of the President’s line of succession.
The first instance of the rule break came back in 2013 when Prince George was set to head off to New Zealand and Australia for a quick tour with his parents. The rule would dictate that Prince George would travel separately from his father, but they all took the same jet. And since then, the family has always travelled together.
The reason for the rule is grim, but it isn’t the only dark regal tradition—here are eight words you’ll never hear the royal family say.
Originally published as The One Royal Rule That Prince William and Kate Middleton Always Break on ReadersDigest.com.