Terry Deary's Horrible Histories series appeals to schoolchildren by including disgusting and true historical details, such as the purpose of the Roman vomitorium. But the author finds modern historians even more nauseating than the Romans.
In comments published in the Times of London, Deary attacked historians in general and Harvard Professor Niall Ferguson in particular for being biased and writing books to further their own reputations. Ferguson responded, "I have read some of the Horrible Histories to my children.... They’re quite funny. And so is this. You say that Terry Deary thinks my book Empire had ‘a political point’. I am not sure what that means. The book argued that there were benefits as well as costs to the British Empire, which is not a political point but a historical judgment. Terry Deary says that he ‘wants to be anti-Establishment’. That sounds more like someone who is trying to get across a political point.”