On Friday, Rt Revd Christopher Lowson of Lincoln, along with a number of barons, will be accused of extorting more than they were entitled to when forcing King John to agree their terms.
What is the Magna Carta?
-Signed in 1215
-Was drafted by Archbishop of Canterbury
-It was made to make peace between rival political groups
-Just four copies remain
The document, created in 1215, laid out the laws of the land.
The event at Westminster Hall in Parliament will see television and radio presenter Clive Anderson play King John and James Eadie QC, who regularly advises the Prime Minister, will act as counsel.
Lord Neuberger, President of the Supreme Court, will be one of those on a panel of judges asked to give a verdict.
Ben Wilson from the Supreme Court in London has been organising the event. He told Premier the bishop and barons will have some tough questions to answer on behalf of their predecessors. He said: "The judges will be seeking to find out really whether they were justified in doing that, because at the end of the day although we've come to know Magna Carta as a great document that sets out all sort of important principles for democracy and the law actually they did do something that effectively defies the King's authority.
"And they essentially had him over a barrel when they encouraged him to sign that treaty.
"So the question before the court will be were the Barons justified in forcing King John to seal the Magna Carta?"
He stressed that this mock trial is a unique way to explore and celebrate the principles the Magna Carta established 800 years on.
Listen to Ben Wilson speaking to Premier's Hannah Tooley.