Prince William, the Duke of Cambridge, his wife Catherine, The Duchess of Cambridge, Prince George and Princess Charlotte arrive at Tegel airport in Berlin, Germany, July 19, 2017.
Prince William, the Duke of Cambridge, his wife Catherine, The Duchess of Cambridge, Prince George and Princess Charlotte arrive at Tegel airport in Berlin, Germany, July 19, 2017. Reuters/Fabrizio Bensch

British royals like Prince William and Kate Middleton travel often to other countries. And while it’s most likely that they would not have to worry about needing an extra shirt or pair of socks, there’s one thing that all members of the royal family must pack in their suitcases at all times, no matter where they are going or how long they will be gone.

According to the Sun, the royal family must always take a black mourning outfit in their luggage every time they leave the country. When William and Kate, the Duke and Duchess of Cambridge, and their children Prince George and Princess Charlotte toured Poland and Germany in late July, it is assumed that they each had appropriate mourning attire packed in their suitcase.

This is for in case Queen Elizabeth II, or someone else in the family, unfortunately dies while they are away. As a royal protocol, all of the Queen’s royal family members must wear black during a mourning period. This ensures that they are dressed appropriately to match the grieving mood of the nation.

It’s a rule now, but there was one time when Queen Elizabeth herself did not have a proper mourning outfit when her father, King George VI, passed away after a long illness. She was in Kenya with Prince Philip in 1952 when the news of her father’s death reached her.

She did not have a black dress with her on the trip, and so she had to travel back to the UK in regular clothes. However, she did not emerge from the public and had to wait on the plane until a black dress was delivered to the aircraft. She had to change into it before she could emerge down the steps and be photographed.

Other royal travel secrets

Apart from the must-have mourning outfit, the royals also adhere to a few more protocols while travelling. According to Hello magazine, William, Kate, Prince Harry and the rest of the family can fly commercial airlines instead of chartered private flights. However, it is preferred that they travel via British Airways to support their own country when using commercial flights.

Last year, Kate boarded the commercial flight of British Airways on her way back to London, surprising her fellow passengers. It was her first solo trip without her husband. (See related story link below.)

The royals are allowed to fly commercial, but never without their security team. They also still need a passport and have to go through immigration. They don’t wait on long custom lines like a commoner, but they still go through it nonetheless. Queen Elizabeth is the only royal who doesn’t need a passport. But again, even she has to go through an identity check every time she flies in and out of the country.

Two heirs must not fly together as well so the royal lineage is protected. However, Prince William appeared to have broken this rule when he brought George on the same flight to Australia in 2014, and again last month during their flight to Germany and Poland.

Apart from having their special monogrammed luggage, which are colour-coded, British royals also sometimes bring their own alcohol with them. The Telegraph’s Gordon Rayner said that their security discreetly carry a bag of their preferred drinks. “Prince Charles and the Duchess of Cornwall sometimes take their own alcohol so there’s no danger of their drinks being spiked,” he explained.

Read more UK royal news:
Kate Middleton boards commercial airline, shocks passengers, as she returns from first solo trip without Prince William
Why Kate Middleton always dresses Prince George in shorts
Why Kate Middleton did not wear a sash to the Spanish state banquet when other British royals did