Most authors have two jobs — writing and the one that pays the bills — but Nicola Morgan has three or four. She is a dynamic lecturer and author of the bestselling Blame My Brain who visits schools to inform children about the vagaries of the teenage brain. She has also written more than 50 educational books for nursery-age children in the I Can Learn series.

But you probably know her through the prize-winning historical fiction that she writes for children aged 11 and over, including The Highwayman's Footsteps and her latest, The Highwayman's Curse.

Inspired by the Alfred Noyes poem about the doomed love between a highwayman and Bess, an innkeeper's daughter, these are gripping, gorgeously written tales of high adventure in 18th-century England and Scotland. Such is their assurance that it is surprising to discover that it took Morgan 21 years to get her fiction published.

“I'd thought — and I'm so ashamed of it — that to write for children you would have to do a simple story in simple language,” she says. “When I realised that you could do deep things in interesting ways, it was a liberating moment.”

Her turning point was reading David Almond's novel Skellig, which one of her daughters pressed on her while on holiday. She realised that the “pretentious, arty, plotless literary fiction” that she had been trying to write for adults was rubbish. The result was Mondays Are Red, about a teenager who wakes from a coma to discover that he has synaesthesia (the condition in which words have colours), which was accepted immediately .

“Before, I was writing for myself, not for readers,” she observes. “Many writers say that you should primarily write for yourself, but I disagree. On one level, you must write from the heart, but especially if you are writing for children, it's for the reader to enjoy. Reading should be for pleasure.”

Morgan is a pleasure to read, both for her prose and her plots. I was so traumatised by Fleshmarket, about a boy whose mother has to have a mastectomy without anaesthetic in 19th-century Edinburgh, that I couldn't carry on after the first chapter — but kids love it, and it became her prize-winning breakthrough.

The daughter of two teachers, Morgan, 46, grew up in a succession of boys' schools, and was something of a tomboy (Bess's pistol-packing in the Highwayman books stem from this, although Morgan says that she lacks the same physical courage) and suffered from a lack of confidence when she won a place at Cambridge to read classics. She knew that she wanted to write, and desperately wanted to avoid being a teacher like her parents. But after university she found herself doing just that (and enjoying it). Experience teaching dyslexic children led her to become an expert in literacy, fascinated by the working of the brain, and she still gets a “tremendous buzz” out of visiting schools to talk about it.

An intriguing mix of highly disciplined intelligence and passionate creativity, she is a born storyteller in the mould of Leon Garfield, Rosemary Sutcliff and Sally Gardner, who can make a historical setting as vivid as our own.

To have persisted in writing fiction despite 21 years of rejection is an indication of her determination. Perhaps this, as well as the school visits, makes her understand how difficult life is for teenagers.

“You can define a teenager in two ways,” she says. “One is universal to all cultures and generations: a state of brain between a child's and an adult's. Special circumstances, such as living through a war, can make that transition much faster, but you still have the teenage brain, and anyone who can remember that time will remember that anger and heightened emotions are a part of it.

“The other way is what's going on now with teenagers. Exams are putting them under huge stress and unintentional pressure, at a time when they are looking ahead towards independence in hope, anticipation and fear. They feel that if they don't pass certain exams they'll have a life that's less good, and the competition for this has become tougher.”

Morgan is fascinated by this tension between permission and oppression, and two of her novels, Sleepwalking and The Passionflower Massacre, are about brainwashing, with chips being implanted in teenagers' brains in one, and the use of drugs in a religious cult in the other.

The Highwayman novels also examine the conflict between citizens and outsiders. The gentle, sensitive, high-born Will flees across the Yorkshire moors from his harsh father and cruel brother, and is held at pistol point by Bess (daughter of the original couple in the poem), who is wounded and desperate. Both fear failing to live up to their parents' expectations. The second book adds in the burden of anger passing down the generations and comes to a terrific climax as the pair rescue an innocent girl chained to a rock with the tide coming in.

Both novels use real historical crises — the Hexham riots in the first, the Wigtown Martyrs in the second — to illuminate the characters' lives. A third in the series is on the way, in which the nascent love between Will and Bess may at last find expression. In the meantime this book has everything young readers (especially boys) want — from short chapters to the enjoyment that comes from encountering characters that they care about, and recognise.

“The 18th century is the perfect combination of the horrible and the modern,” Morgan says. “It's dark and rich in gruesomeness, but you know that the Enlightenment is coming.”

The Highwayman's Curse by Nicola Morgan

Walker, £6.99; 368pp

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