While the Physician to the King might not always travel with King Charles, there is one medical person who will always be in attendance: a Royal Navy doctor. In an essay for the Telegraph, writer Gordon Rayner, who traveled with Queen Elizabeth for 20 different royal tours, detailed what exactly the Royal Navy doctor does for the monarch while traveling. The doctor's duties include learning which hospitals are near their destination; keeping a medical bag, which includes a defibrillator, in tow; and staying close by should a medical emergency arise. If there's an attendant holding a medical bag seen near the monarch in a photo, it's more than likely a Royal Navy doctor.

Royal Navy doctors don't just travel with the head monarch, though. The position can entail a variety of assignments. As noted in the official job description, Royal Navy doctors go through position-specific training, and then they're sent all over the globe to provide medical care. There are several different paths a Royal Navy doctor can take, but they all begin as General Duties Medical Officers. In addition to having proper medical training, Royal Navy doctors must have a high enough academic record to qualify for the position. Royal Navy doctors also have to meet certain physical criteria, including maintaining a specific body mass index and passing the Naval Swimming Test, a test that everyone must pass in order to join the Royal Navy.