Do you know the answer to this question? As follows. ‘Which war saw the first major use of hot air balloons?’

Well, if only someone had given the answer to me, aged ten. A true aficionado, ten-year-old me entered the Horrible Histories tenth anniversary competition. After popping to the post, however, I realised I’d got a qualifying question – that question – wrong. In sorry tatters lay my wispy wish to meet the makers of my favourite history books. I like to think I eventually got over this unhappy episode.

No irony was lost on me, then, while I sat, aged twenty-one, in an Oxford Literary Festival workshop, watching illustrator Martin Brown entertain a cosy audience. The average age of my co-spectators was approximately eight-and-three-quarters. A little awkward, perhaps. But eleven years late is better than never, I suppose.

“That’s a potato,” exclaims Brown, leaning back from a dubious attempt to draw a freehand circle. Cue wild giggles from the small crowd, enraptured by his scribble. He tries drawing a horse. “There’s a technical term for drawing things like horses,” he remarks, pausing: “Hard.”

When calling to mind the Horrible Histories series – described by publishers Scholastic as their “crown jewels” – readers will often check Terry Deary, who wrote them. Yet how much text could you quote? Or do you immediately see the loud, vibrant illustrations of Martin Brown, which, as a friend of mine once swore, “terrified the living Christ out of me”? His boisterous characters, robed in rudely faithful detail, are the skin of the memory, the faces of the horrible history cherished by many an impish childhood.

I put this to him afterwards, in a quiet, appropriately antique back room. You’re basically Horrible Histories, I said. Anyone else drawing the books wouldn’t be quite the same. “That’s very kind of you to say,” replied Brown, “but I wasn’t the only illustrator!”

This modesty is characteristic of him. Brown is usually tucked up in Dorset with his wife and daughters, out of public view – in stark contrast to partner-in-crime Deary, who periodically frequents the broadsheet interview circuit. Even just a few months ago, I was convinced he was living in Australia.

Not so. He’s been hoofing around this sceptred isle since 1989, a suitably historic year by all accounts. Brown’s first step on the ladder was a Scholastic series titled Coping With – teachers, parents, and so on – for which Brown and the author, Peter Corey, put together histories on each subject. “We liked it so much, we asked: could we do a Coping With History? The editors tapped their noses and said, ‘Hold that thought. Something’s come through I think you’d be interested in.’” Terry Deary had sent in a manuscript.

Thus, a partnership was ordained – “a perfect symbiotic relationship”, declares Brown. But with Deary in Durham, they generally don’t get much facetime. No dinners at Terry’s? “There would be if we were a tad closer. I’d like to see him more often, socially.” He laughs. “But we get along brilliantly.”

Brown spent his Melbourne childhood “constantly doodling”. Unsurprisingly, he excelled at art. He laments complacency though, and “very nearly failed” in sixth form; having intended to enter graphic design, he started training as an art teacher instead. But he didn’t even finish that, scuttling after three years to be a dogsbody in an ABC television studio. At no point, however, did he ever drop his pencil: always experimenting, always drawing.

Brown’s craft found a home, but only after upping sticks and ending up in London. He worked at Harrod’s (“I’d draw the customers and stick them up where they couldn’t see them”) before landing a job at London Graphics, which delivered art supplies to practically everyone who was anyone in the publishing world. By sheer sudden luck, he was at the heart of the business, with pretty much every phone number of every potential employer in the country on his desk.

His itinerant streak resurged. “I thought one day, ‘now or never’: I quit, called myself a cartoonist, stocked myself up with as many numbers and names I could remember, and started phoning people.” Then he took to the doorsteps, and the rest is, of course, horrible history.

Brown’s visual style is distinctive: all huge goggling eyes and big squidgy noses dressed up with exquisite historical precision; precision that he used to get from children’s non-fiction sections of libraries and, these days, from Google Images. He still nurses a soft spot for titles like The Vicious Vikings and The Savage Stone Age (“for once I could relax a bit about the costumes”). The jokes are impressively, effortlessly witty. Considering the young audience, the humour has remarkably sophisticated, age-wide appeal. Was that deliberate? Where did that come from?

From wide set of influences, it turns out. Illustrators, like Andrew Loomis, and strip cartoonists, like Johnny Hart, creator of B.C. (“where I get my eyes from”). Brown’s most intriguing inspirations are the great American editorial cartoonists, names like Ron Cobb and Pulitzer recipient Jeff MacNelly, father of the Shoe comic strip. “If I could get those wry payoffs, growing up,” he maintains, “I don’t see why kids today couldn’t.”

In fact, so thoroughly is Brown immersed in the cartooning tradition that he wears the badge ‘illustrator’ with humble disquiet. “People call me an illustrator. I’m not,” he grins. “The world is full of amazing illustrators. I’m happy to do it, but I’m not so big on colour, or picture design. It scares me a bit – give me a four-strip ba-boom gag and I’m happy as larry.”

Perhaps the editorial cartoonist’s mantle appeals, given his heroes? Like fellow children’s illustrator Chris Riddell, who has gone from carving dragons and monsters on the page to carving up George Osborne in the Observer. “Jealous? Oh, absolutely,” says Brown emphatically. He’d jump at the opportunity. “Editorial cartooning is the pinnacle of the art. Chris Riddell aside, I actually don’t think it’s always done particularly well in this country. I grew up looking at Australian and American editorial cartoonists, books and books of just stunning stuff. To be able to both produce such beautiful pieces of artwork, and include just that clever little twist or dig… it’s genius.”

And serious, too. “There are cartoonists outside the West doing what I’d be too timid to do, and being threatened and banned and all sorts, just for shining a light,” he adds admiringly. Portraying the past is, however, weighty work as well, as he is keen to stress. History, after all, is just another battlefield: his own way of paying his dues to truth.

The ten-year-old in me reluctantly anticipates the end of the hour, but insists on one last act. Awkwardly, I push forward a natty blue exercise book. It’s an imitation ‘Horrible Histories’ I drew in primary school, one of many inspired by his illustrations. He picks it up and flicks through it, smiling interestedly at my pencil frieze period figures, all wearing his signature eyes and noses.

“Well, I love these,” he murmurs brightly, “They’re charming.” He might be lying, but that hardly mattered. I had fully reverted from interviewer to child. “Will you sign it?” I ask, rather sheepishly. Of course he would. “But it’s usually the author who signs his own book,” quips Brown.

In my mind, I was back in the workshop audience. My ten-year-old self is gripped. I know the answers now. The war that saw the first major use of hot air balloons? The American Civil War, of course. Stepping away from the whiteboard, Martin Brown turns to offer a tip. “Keep drawing,” he urges, “If you don’t, your horse will always look like a sausage.”