Which is why it comes as no surprise that these stipulations are even extended to their suitcases.
Before leaving the UK, every member of the Royal family must pack a 'black mourning outfit', according to The Sun.
In the unfortunate event that a Royal should pass away while they're travelling, they must return to the country in the traditional garments to show their respect.
And there is good reason for the rule. In 1952, Queen Elizabeth II was on a Royal tour of Kenya with Prince Philip when her father George VI died.
Unprepared, the Queen had to wait on the plane until someone brought her a black outfit before she disembarked - otherwise it would have looked inappropriate and disrespectful.