The rarest passport in the world is so exclusive there are only three in existence
It's thought the measure of a passport's power is the number of countries it allows its holder to travel to without applying for a visa.
Based on this, German passports - held by millions - have the most clout, allowing their citizens to go to a total of 176 countries out of 218, visa-free.
While millions don't hold a passport for the Sovereign Military Order of Malta, it is precisely their rarity which makes them so special.
Only three are issued at any one time.
These go to the three highest officers in the Catholic order: the grand master, deputy grand master, and chancellor.
So what is the medieval order?
Its full name reads the 'Sovereign Military Hospitaller Order of Saint John of Jerusalem of Rhodes and of Malta.'
It originated as the Crusader Knights Hospitaller in...