The Magna Carta was medieval England's "Russell Brand moment" which didn't bring an end to the 'civil war' between the nobles and monarchy, according to David Starkey.
The controversial historian was at Runnymede for the 800th anniversary celebrations of the signing of the Magna Carta in 1215 in the presence of the Queen and the Duke of Edinburgh, a situation he described as "extraordinary".
The Queen was joined by other senior royals at the special event at the site where King John accepted the historic document that limited the power of the Crown on 15th June, 1215.
"I find it extraordinary that we're dragging the poor Queen here to commemorate the second greatest humiliation in the history of the monarchy," Starkey told ITV News.
"Are we going to have her re-enact the execution of Charles I, I wonder?"
Asked about the effect of the first Magna Carta, Starkey was scathing, saying: "The Magna Carta of 1215 fails. It's a Russell Brand moment - far too extreme, far too republican, far too anarchical."
However, he quickly asserted that after King John died the document was revised the following year by the prince regent, William the Marshal, whom he described as a "Tory prime minister with brains" and who created a better document - for most.
"He has the genius idea of reissuing Magna Carta with all the difficult bits left out.. all those republican bits, those bits about civil war, the treatment of the Jews - they're all cut out and you have a nice English compromise."
Starkey went on to say the concept of the Magna Carta was still hugely relevant hundreds of years on, and something that laid the foundations for the political system we have today and for which others would die for.
"In Russia, in China, in most of Asia, in most of Africa, people would cut their throats for the rights we had 800 years ago."