When the 800th anniversary of the signing of the Magna Carta was celebrated in June, Christchurch's University of Canterbury decided to dig out its own 500-year-old copy.
But when they took a closer look at an inscription on the title page, they realised their copy was an historic document in its own right, with a connection to Henry VIII, the king who had six wives and had two of them executed.
Its been 800 years since the Magna Carta was signed. It guaranteed the people certain rights and laid the foundation for what came to be known as the rule of law.
It's so valuable and delicate, the pocket-sized document can't be touched; it can only to be looked at from behind the glass.
Just like the original, this Magna Carta is hundreds of pages long, written entirely by hand, in Latin. The original was a deal between the King of England and a group of rebel barons 800 years ago.
But an inscription on the University of Canterbury's 500-year-old copy places it right at the centre of the reign of King Henry VIII.
"If you focus in very closely here you can see just in the bottom half here the words 'Richard Samson, dath own me' in a Tudor stationary hand," says historian Dr Chris Jones.
That's King Henry VIII's own lawyer, his divorce lawyer.
"Samson is the man who executed Anne Boleyn," says Dr Jones. "He is the man who is the King's proctor. He's the man who puts the case for the King's divorce. So he is really at the centre of Tudor politics."
The execution of Ms Boleyn is a story that has been recreated dozens of times by Hollywood.
Now a reference book belonging to the man who made it happen, it plays a major part in the university's book collection.
It's a connection that's gone undiscovered since the document arrived in New Zealand in 1932.
"It's travelled all the way here from the United Kingdom to New Zealand, and up until about a month ago no one knew whose it was and what significance it had," says Dr Jones.
The university's little piece of Tudor treasure is on display for a month.