A man has been arrested on suspicion of trying to steal the Magna Carta from Salisbury Cathedral, Wiltshire Police said.
In the bizarre incident the 45-year-old man was seen trying to smash the glass box which protects the Magna Carta, which set off alarms.
In a statement, Wiltshire Police said: "Shortly before 5pm yesterday (Oct 25) alarms were activated at Salisbury Cathedral after an attempt was made to smash the glass box surrounding the Magna Carta.
"Staff were alerted and police were called.
"A man matching the description given by witnesses was arrested on suspicion of attempted theft, possession of an offensive weapon and criminal damage, and has been taken to Melksham custody for questioning where he remains.
"The Magna Carta has not been damaged and nobody was injured in the incident.
"We are aware there were a number of witnesses to the incident who may not have spoken to police. If this was you, please get in touch via 101 and quote crime reference number 541800101438."
What is the Magna Carta?
Magna Carta was issued in June 1215 and was the first document to put into writing the principle that the king and his government was not above the law. It sought to prevent the king from exploiting his power, and placed limits of royal authority by establishing law as a power in itself.
The Magna Carta was a document signed by King John after negotiations with his barons and their French and Scots allies at Runnymede, Surrey, England in 1215.
It is one of the most celebrated documents in the History of England. It is recognised as a cornerstone of the idea of the liberty of citizens.
In 2015 the Magna Carta was 800 years old and was taken on a 'tour' on the UK and Europe.