Philippa Gregory is late sending in the manuscript of her latest novel. The former journalist in her is pained at missing a deadline but in her defence, it covers 40 years in the life of Margaret Pole, the last Plantagenet princess, who was wrongly accused of plotting revolution and executed by Henry VIII at the age of 67. “There was rather a lot to fit in.”

The King’s Curse will be Gregory’s 25th novel (she has also written three books for young adults) and, judging by past successes, is destined to be another bestseller.

She is a giant of historical fiction with millions of fans all over the world hooked on her compelling tales of history’s fascinating but largely forgotten women.

Her 2001 novel, The Other Boleyn Girl, was turned into a Hollywood film starring Scarlett Johansson as Mary, sister of Anne and mistress of Henry VIII, and a second TV series of The White Queen, based on her series The Cousins’ War, is currently being filmed.

Historian David Starkey may sniff that Gregory’s novels are “good Mills & Boon” but it’s clear who’s having the last laugh.

Ironically, Gregory hated history at school and only scraped an E at A-level: “It was taught very badly and very boringly.”

When she came to University of Sussex it was to study English but the university’s insistence on multidisciplinary learning meant she had to take two additional subjects besides.

Choosing history changed her life.

“I had a wonderful tutor called Maurice Hutt who demonstrated how thrilling, innovative and powerful the study of history is and that was it.

I wanted to know everything.”

She went on to do a PhD at Edinburgh, intending to become an academic, but was unable to find a position.

“It was the 1980s and Thatcher was cutting university courses really savagely. When people left posts they weren’t replaced. It’s never exactly boom time for 18th-century history and it became apparent I wouldn’t get a job.”

She began writing a novel mainly for her own amusement.

To her continuing amazement the book – Wide Acre – was picked up by both British and American publishers and went on to be a bestseller in both countries.

Being presented with a lucrative opportunity to lose herself in research was too much to resist and Gregory swiftly became a full-time writer, abandoning both notions of academia and her earlier journalism training.

She had spent some time working at The News in Portsmouth and had apparently always dreamed of a job at The Argus but golden weddings and town planning meetings failed to hold her attention. “In journalism you almost don’t want the answer you’re not expecting; in academic study that’s the very best outcome.”

Her nose for a good story continued to serve her well, however; when Gregory “discovered”

Mary Boleyn, she had been all but forgotten.

“There wasn’t a single book or essay about her. She was in the footnotes of other, allegedly more interesting, lives and only very occasionally at that. It took an exjourno and a woman historian to spot that actually she was rather extraordinary.”

To this day, Gregory is amazed at the patchy recording of women’s history – “We don’t even have a birth date for someone as famous as Anne Boleyn!” – and has made it her “life’s work” to balance out the history books.

“Even now there’s a prejudice that women didn’t operate the levers of power, weren’t effective and are innately not interesting.”

Gregory has robustly disproved this by taking readers directly to these women’s worlds, which were frequently just as interesting as their more famous husbands and peers.

“I want to look out through the characters’ eyes and see the world as she would have seen it.”

This usually means up to a year spent locked away with a pile of textbooks on the North Yorkshire farm where she lives with her third husband.

“It’s the only way I know to make a novel absorbing.

You have to experience the feeling of being there yourself and for me that means reading all the materials, going to the places, looking at the clothes, understanding the medicine.”

Although Gregory will readily admit she is “in the entertainment business” and has a duty to make her stories engaging, she prides herself on her commitment to historical accuracy. It’s mainly to avoid “breaking the spell”

for readers, she explains.

While people will always disagree about the interpretation of historical characters – “If you and I had a mutual acquaintance it’s unlikely we’d hold exactly the same view of her and we’d both have evidence to support our views” – there is no place for historical anachronism in Gregory’s world.

“I remember years ago reading [Hugh] Walpole’s novel on Judith Paris and she escapes by opening a window and climbing down a drainpipe – before sanitation had been invented. I was loving the novel up until that point but it completely lost me then and I always hold it in my mind as the sort of thing I don’t want a reader of mine to experience.”

It’s not easy, she adds. “I have to be very careful not to say someone’s touch was electric or their appeal was magnetic when I’m writing about the Tudors or whoever.”

But while she has some sympathy for old Walpole, she is more exacting about TV producers taking liberties. As one of six executive producers on The White Queen, she read every script, watched nightly rushes (the first versions of filming) and sent helpful notes and suggestions.

It was presumably hard therefore when a handful of the show’s 5.3 million viewers grumbled about the appearance of zips and handrails and claimed The White Queen’s clothes were “too white.”

But she appreciates TV is a different medium with its own demands. “I’ve spent 30 years writing. I really know how a Philippa Gregory novel works. But I’m relatively new to film and TV and I have to approach it with the appropriate humility.”

Given her fascination with kings and queens of the past, it comes as some surprise to learn that Gregory is a republican whose interest in our current monarchy is about as great as her interest in reality TV family The Kardashians.

“I have no particular interest in the goings-on of a group of wealthy, privileged people... it seems to me most of what they do is just gossip.

“There isn’t any real power there. They’ve become celebrities more than anything else and that doesn’t interest me at all. I’m in favour of a reduced monarchy. I think the idea of a social structure that isn’t democratic or meritocratic has no real place in modern society.

“The Tudors are interesting to me because the personality of the monarch determined their political role and vice versa. The sort of person they were affected the whole kingdom. But that hasn’t been the case for a long time now.”

We return to her new, slightly belated book (don’t worry Gregory fans, she promises me she will file it the next day). Does she have even the slightest attack of nerves about a new release?

“Of course you worry about whether it will be successful. Aside from anything else, I’ve spent two years of my life on it. But it’s rather like sending a child off to university; there’s a point where you think, ‘Well, I’ve done the best I can, it’s up to them now.’”

*Philippa Gregory is a guest speaker at Myriad’s First Fictions literary festival, which takes place at West Dean, near Chichester, until Sunday (April 13). To book, visit first-fictions * For more information on Philippa Gregory, visit