The always humble David Starkey shouted down a human rights lawyer on the Today programme this morning by claiming: "I"m the historian here, I'm a great historian."
Starkey, who 'accidentally' called former HuffPost UK Political director Mehdi Hasan "Ahmed" during an edition of Question Time, told human rights barrister Baroness Helena Kennedy she was wrong to emphasise the importance of Magna Carta during a debate on the 1215 document.
He was promoting his new book in which he argues revisions of the document, written until 1225, were far more important.
Pinko BBC deliberately omits 'great' from Starkey's job description
He said: "I'm the historian here." At this point, his ego took full control of his mouth and added: "I'm a great historian."
It prompted tweeters to compare him with Judge Dredd.
And call him a "bully" who "gives historians a bad name".
Kennedy and Starkey's discussion started with the historian saying the 1215 document Magna Carta was more revolutionary but less consequential than we believe, because "the difficult bits" were left out of subsequent versions.
Kennedy, who said she enjoyed Starkey's book and, to be fair to him, was the first to call him a "great historian". But she said Magna Carta was more important than he claimed.
Starkey said: "Helena is talking about it as a lawyer and lawyers are no good as historians. They have no sense of time."
Presenter Mishal Husain later tried to intervene.
Mishal Husain: And the rights it confers, it's very much the rights on 'free men', it's not every man who's going to benefit.
Starkey: Ah, no. 1225, this is...
Husain: 1215
Starkey: Stop talking about 1215. 1215 doesn't matter. It's only your media fixation with your day's anniversary.
Husain: Because the anniversary is important
Kennedy: No, David...
Starkey: No Helena, let's correct facts, I'm the historian as you've pointed out and I'm a great historian.
This last bit was met with howls of laughter from Husain and Kennedy.
Kennedy told Starkey he was being pedantic, prompting the great historian to shout: "I'm not!" and spoke over her saying: You're a lawyer and you see accuracy as pedantic?"
As she said there were fundamental similarities between the 1215 and 1225 versions, such as establishing trial by jury, Starkey spoke over her again, repeating: "This is lawyer myth."
He added: "No, that is myth," to clarify his position.
After this, Starkey let Kennedy speak for a brief period, saying why she thought the 1215 document was the beginning of a movement towards curtailing the power of kings.
Husain closed the segment saying: "Perhaps we can agree there is space for both lawyers and historians."
Starkey added: "Cuddling up to each other in front of the microphone, yes."