A man has been jailed for attempting to steal a "priceless" version of the Magna Carta from Salisbury Cathedral.
Mark Royden, 46, was convicted of using a hammer to smash the protective glass box surrounding the 800-year-old manuscript on October 25, 2018.
He was jailed for four years at Salisbury Crown Court on Friday.
During the trial, jurors hear that Royden turned a CCTV camera in a failed bid to avoid being recorded by it and set off a fire alarm as a distraction.
He then smashed the security case in the Chapter House holding the artefact.
After his attack on the case, he was pursued by "good-spirited" members of the public including a pair of American tourists, cathedral staff and stone masons - who detained him in a works yard outside.
Royden was found guilty at Salisbury Crown Court of attempted theft of the Magna Carta and criminal damage to the display case costing £14,466 to repair on January 20 this year.
Sentencing Royden, Judge Richard Parkes QC said: “This was a determined attempt on a document of huge historical importance.
“Magna Carta is a document of huge importance to our country and many other countries that share our democratic traditions.”
The court was previously told that Royden has 23 previous convictions covering 51 offences, including theft and criminal damage.
The 46-year-old, who suffered brain damage in a car accident in 1991, was subject to a court of protection order regarding his finances and is aided by a carer.
Salisbury Cathedral's version of the Magna Carta is one of four that remain in existence from the original 1215 charter.
King John issued the Magna Carta after agreeing peace terms with a band of rebel barons, and it is now one of the world's most celebrated legal documents.
It established for the first time that neither monarch nor government was above the law and set out principles of liberty.
The Salisbury copy went back on display three months after the incident, with the damaged case being made part of the exhibition telling the document's history.