Travel secrets of the royal family revealed

William and Kate, the Duke and Duchess of Cambridge, with Prince George and Princess Charlotte arriving in Victoria, British Columbia, in 2016. Photo / Jonathan Hayward, The Canadian Press

The royal family are a jet set bunch. In an average year there are an average of 3500 royal engagements attended around the world.

However with great travel privileges come great responsibilities - as well as some wonderfully bizarre rules.

Here are the royal travel secrets and duties that the royals have to follow when leaving the country.

The Queen doesn't have a passport

Her majesty the Queen is the only British national who doesn't need a passport to travel. Given the passports are issued in her name, it is considered redundant.

Queen Elizabeth and Prince Philip arriving at Perth International Airport in October 2011. Photo / Lincoln Baker, AFP

The royal household's website clarifies: "As a British passport is issued in the name of Her Majesty, it is unnecessary for The Queen to possess one."

The rest of the royals must carry a passport, although this will change when Prince Charles becomes king.

However, Elizabeth II still has to go through identity checks and proof of address when she exits or enters the country.

Prince William and Prince Charles cannot share a plane

Some royals cannot travel together. The royal heirs to the throne cannot risk being on the same plane, in case of accident.

As first and third in line to the throne, Prince William and Charles cannot fly together. Similarly the Queen and Charles cannot share transport. Prince William and son George are also barred from sharing the same plane, to insure the royal lineage is not lost should there be an air accident.

William and Kate, the Duke and Duchess of Cambridge, with Prince George and Princess Charlotte arriving in Victoria, British Columbia, in 2016. Photo / Jonathan Hayward, The Canadian Press

This rule is not as hard and fast as others. In 2014 the Queen granted special allowance for the Duke and Duchess of Cambridge William and Kate to fly with their son, nine-month-old Prince George to Australia.

Royals always have a black outfit packed

No matter where they go, royals always take black formal wear.

This morbid rule is to make sure they are always prepared with suitably mourning attire, should another member of the family die while they are abroad.

The Queen was famously unprepared for the news that her father, King George VI had died, while in the Treetops hotel in Kenya.

Royals carry an emergency blood supply

Preparedness for disaster follows the royals wherever they go. In some cases this involves carrying their own blood supply while abroad.

The Telegraph's chief reporter and former royal correspondent, who attended over 20 royal tours, Gordon Rayner revealed that the royal medical emergency bag is far more than your average first aid kit.

He described it as "a bulky medical bag containing a mobile defibrillator and all manner of emergency medicine," just in case something happens.

One presumes these blood bags are blue?