My daughter, who is an academic historian, and just general reading. David Cameron made him his 'history tsar' and historians were up in arms about it. I read some of the arguments. One of his gems was that J M Keynes was a rubbish economist because he was gay and, therefore, didn't have a stake in society and the future. Ferguson and Paul Krugman have frequent online spats, which are sometimes quite entertaining.
Incidentally, the 'any' should have read 'many'.
He's highly controversial - as I wrote, he's the Marmite of historians - either love him or hate him. His speciality is counterfactual history ie 'what if...' history, which is standard fodder for conspiracy sites. Fascinating to read and makes the headlines, but not always much evidence. His real talent is self-publicising.
If you look at his Twitter account, he says that he made a mistake about supporting Brexit and should have listened to 'the man down the pub'. Why? He's spent his whole life researching and writing about history. Surely he should know a bit more than the man down the pub. Is he trying to appear a non-expert, because it's suits the times? Tut tut! Surely not!
This is being reported originally by Breitbart, which I'm sure you know has connections to the right wing in America. Trump has named Breitbart's former CEO, Steve Bannon, as his chief strategist and Raheem Kassam, Breitbart's London editor, was going to run as leader of UKIP. He was Arron Banks' favourite.
So much for these elite conspiracies Farage & Co whinge about, huh? Are you beginning to see similarities?