Known as the final resting place of Æthelstan, the first King of the English, Malmesbury Abbey has a long and varied history, being established in the seventh century in the village of Malmesbury in Wiltshire. It's one of the only English religious houses with a history lasting from the 600s to the dissolution of the monasteries under King Henry VIII.

However, there was a little-known and rather dark period of the abbey's history, which was only recently discovered by local historian Tony McAleavy. While researching the history of Malmesbury, Tony discovered that this beautiful abbey once housed a murderous monk named John of Tintern. Speaking to the BBC about his discovery, Tony compared this monk, who ended up being elected as Malmesbury's abbot, to a "gangster."

He said: "He operated as a gangster and a gangster who was prepared to kill or have his enemies killed."

John had a rather long criminal record, beginning in 1318, 22 years before he became Malmesbury's abbot. His first crime saw him brought in front of King Edward II and accused of taking part in a "mass brawl."

Then just a couple of years later, John, and the other monks at Malmesbury became embroiled in hiding £10,000, which would today equal millions, from the crown.

This money is believed to have given to the abbey for safekeeping by the Despenser family, who were staunchly loyal to Edward II. Following the King's deposition and the Despensers execution, the monks kept the money secret for around ten years.

After this was eventually discovered, John once again found himself in legal trouble, however King Edward III decided to pardon him and the other monks after taking the £10,000 back.

But it wasn't just brawling and theft that would see John go down in history as a rather disgraceful monk. Despite having taken vows of celibacy he openly lived with and publicly flaunted his relationship with Margaret of Lea.

He was even accused of burning down Margaret's house, where she had resided with her husband, and abducting her.

John also faced accusations of murder, having hired an assassin to kill a number of people, most of whom were local gentry or tenants living on abbey land. Tony suggests that this was so he could grant the land to his own "cronies" instead

Eventually, all of these accusations saw an arrest warrant go out for John, and both he and Margaret went on the run. However, despite being accused of murder rather than facing jail or the death penalty, John was ultimately sentenced to £500, the equivalent of hundreds of thousands today.

Following his career as both a monk and a criminal, John died in 1349, with some suspecting that he had fallen victim to the black plague.

However, prior to his death, John appears to have sought absolution for his crimes, writing to the Pope to seek "indulgence", meaning that his sins would be forgiven at the moment of his death.