Queen Elizabeth II carries a bag full of blood with her whenever she travels abroad so she could use it in case of emergency, according to a royal expert.

Queen Elizabeth is one of the most-traveled heads of state around the world, where she has already visited most countries since she ascended into the throne in 1952. But because of her prominent position, Her Majesty should carry a bag full of blood in case of emergency - as well as her immediate heirs, Prince Charles and Prince William.

Royal expert Duncan Larcombe told Yahoo's The Royal Box that whenever the monarch is going on a tour, a royal physician comes with her and brings a bag full of their blood. This is something that they do, just in case something happens to the Queen, as her health comes first when traveling abroad.

If Her Majesty is visiting a country where reliable blood supplies are questionable, then a bag of blood is always included on her royal luggage, as reported by Express UK. So, in the case of blood transfusion, Queen Elizabeth's health wouldn't be put at risk. After that, emergencies will quickly respond as the monarch's doctor is always nearby when she travels.

The medical practitioner is reportedly a Royal Navy doctor who always brings a bulky medical bag which contains emergency medicines and a mobile defibrillator. Also, the doctor makes some careful research to find out where the nearest hospital is to Her Majesty all the times.

Since Prince Charles and Prince William are second and third in line to the throne, both of them were also required to follow the same rule when traveling abroad. Also, royal family members reportedly have a set of items they bring along - such as a black outfit - when going to another country.

This rule was reportedly imposed to make sure that royals are wearing the right clothing when they come back from a tour abroad in mourning. That was the case when Queen Elizabeth returned from a visit back in 1953 after the death of her father, King George IV.

Queen Elizabeth also brings a camera whenever she travels abroad on official duties, as revealed by journalist Phil Dampier in his book What's in the Queen's Handbag and Other Royal Secrets, who's been writing for the royal family for over 30 years.

The Queen has been spotted on several occasions taking photographs, particularly during her younger years and on state visits. The monarch puts the camera on her handbag, and it's reportedly being used to take pictures of visiting presidents and other VIPs.