Author Terry Deary was initially skeptical about a TV adaptation after a negative experience with a 2001 animated series that had only loosely incorporated his concept, and only agreed to the new project on the condition that it be explicitly "horrible, funny and true".

Early concepts for the show involved framing devices such as a ghostly train carrying children into the past or a wizard storyteller guide, before producers decided the material was strong enough to stand on its own as a live-action sketch show.

To set the tone for the writing team, adult historical satires like Blackadder and the Monty Python films were screened at the very first writers' meeting.

Writer Laurence Rickard was originally recruited solely for the writing staff, but ended up joining the starring cast after creating the character of Bob Hale, whose convoluted monologues proved impossible to hand over to any other performer.

Sarah Hadland left the show after the second series but returned with an 'also starring' credit for the fourth and fifth series.

Filming took place over eight weeks both on location and at London's Twickenham Studios, with the rapid pace of shooting thirteen episodes' worth of material meaning performers had very little time to prepare, leading to frequent improvisation.

Prop food was often modified for gross-out effects, with melted chocolate bars standing in for excrement and soup used to represent vomit.

After the unexpected success of the song 'Born 2 Rule' (featuring Kings George I-IV as a boyband) in the first series, the creative team decided from series two onward to make all comedy songs self-contained music video parodies matching historical figures to modern musical genres.

The song 'The Monarchs' Song', listing every British monarch since William the Conqueror in a Chas & Dave-inspired cumulative format, was deliberately written to challenge young viewers after the team noticed children memorizing lyrics from earlier songs.

The recurring 'Horrible Histories Movie Pitch' sketches, featuring League of Gentlemen actors Mark Gatiss, Steve Pemberton and Reece Shearsmith as Hollywood producers, parodied the format of a former Orange cinema commercial campaign reminding audiences to turn off their mobile phones.

In September 2014, the BBC Trust ruled that a sketch implying Florence Nightingale rejected Mary Seacole's nursing application for racially discriminatory reasons breached editorial guidelines due to insufficient historical proof, leading the BBC to pull the sketch from its website and future broadcasts.

Production assistant Greg Jenner, self-described as a 'tyrannical pedant', vetted all historical material used on the show and stated that he counted only eight errors out of more than 4,000 facts presented across the show's run.

When an error was found, the show attempted to correct it going forward: the 2009 song about the Hanoverian Georges originally said George I 'died on the loo,' but this was correctly reassigned to George II for the 2011 BBC Proms reprise.