WHEN you consider that love is universal, crossing borders around the world, it's perhaps no surprise that Mills & Boon publishes in 26 languages across 109 counties, selling one book globally every four seconds.

The UK’s leading publisher of romantic fiction was established in 1908 and today it has more than 1,300 authors penning stories of love in its many guises, from contemporary romance and historical drama to romantic comedy and erotica.

Susan Stephens, of Hartshead, has sold more than eight million copies of her Mills & Boon books, and recently launched her 50th novel, In The Sheikh's Service.

She has been writing for the publisher since 2002, thanks initially to a twist of fate. "I went to an auction and one of the lots was a chance to 'be an author for a day' with legendary Mills & Boon author Penny Jordan; my husband bid for me and I got it," says Susan. "Penny and I hit it off, both being big dog lovers, and we remained close friends until her death. She was a very generous-hearted woman, she was a friend and mentor and was very encouraging with my writing."

Susan had already written a manuscript about her eldest child's experience of childhood asthma, called Help Me Mummy, I Can't Breathe. She later wrote a romance and submitted it to Mills & Boon. "I got a rejection letter back and thought I was rubbish. I realise now how wrong I was, as they don't write to you unless they think you have something promising," says Susan.

Her first Mills & Boon title, A Spanish Inheritance, was published in 2003. Thirteen years later she's a best-selling romantic novelist, with 50 books under her belt. Susan's books are translated into many languages, and she recently had one published in Chinese in a comic book style, Manga, published by Harlequin.

Her passion for romance could be inspired by her own love story - Susan met her husband on a Monday and, in true Mills & Boon style, they were engaged the following Friday and married three months later!

"We met in Malta; we were both ready, we both wanted a family and we were very lucky," says Susan. "We had to get to know each other afterwards, and thankfully it worked. We now have three children and five grandchildren."

Before she began writing Susan was a professional singer, having trained at the Royal College of Music. "I've always been an entertainer, writing is just another form of entertainment," she says. "I was an only child and escaping into a book was my greatest pleasure."

So what's the enduring appeal of Mills & Boon? "Love is universal," says Susan. "The more trouble and unrest there is in the world, the more people want to believe in love and its endless variations. People want escapism - why shouldn't they believe their prince will come?"

There was a time when you'd be forgiven for thinking of Mills & Boon as several variations of the same love story, often involving air hostesses and pilots, or kitchen maids and lords of the manor. But it has, says Susan, evolved. These books are written by women, for women, and are stories of female triumph. With titles such as The Millionaire's Snowbound Surrender, Reawakened by the Surgeon's Touch, and Kidnapped by the Highland Rogue, romance is still key, but the genres are more varied - there's even a steamy erotica range - and today's heroines are pro-active, some with jobs as engineers and airline pilots.

"Some readers want hot romance, some love medical or historical romances, others like intrigue and suspense. There's something for all tastes," says Susan, whose books veer on the "hot side".

"I write high fantasy - sexy, glamorous worlds populated by Greek billionaires, sheikhs and polo players, who are my 'European cowboys'," she smiles.

In her latest book, In The Sheikh's Service, the hero, Shazim Al Q’Aqabi, is horrified to discover that the woman set to fulfill his late brother’s conservation dream is the exotic dancer he encountered in London. Feisty Isla Sinclair proves irresistible to Shazim, who has been a slave to duty all his life and is now considering "a far more pleasurable way to spend his nights under the desert stars". But acting on his desire for such an unsuitable woman is tantamount to treason, leaving the sheikh facing the hardest decision of his life…

"The story follows a series of misunderstandings," says Susan. "I like a bit of verbal jousting and banter, but this kind of writing isn't chick lit. It has more emotional depth - grand opera, rather than musical comedy."

Susan writes about 50,000 words a novel but says that, contrary to popular belief, the Mills & Boon criteria isn't too strict. "The idea of it being formulaic is a myth. Everyone has their own way of going about it," she says. "I focus on the main couple and have a very set idea before I start writing. The reader has to be confident that the hero isn't going to leave the woman in the lurch. There needs to be some conflict along the way, but I don't do love triangles.

"I'm a firm believer that you must start with character, not plot. The books I feel are flat are those where I don't care about the characters."

Does she have an ideal hero? "Mine tend to be swarthy, dark and noble," says Susan, who writes standalone titles and the occasional series.

"I love taking readers into a world I've created. I'm inspired by places I've visited, particularly Tuscany and the Canary Islands. Sometimes an island will crop up in a story and I have somewhere specific in mind. I'm just finishing a book set on a Greek island."

The digital age has created a new trend in publishing. A story that starts off circulating on social media can become a global best-seller - as EL James proved when she posted her erotic Fifty Shades of Grey trilogy online and it went on to sell more than 100 million copies worldwide, setting a record in the UK as the fastest selling paperback of all time. The second Fifty Shades movie is released next year.

"Self-publishing is mainstream now, publishers have to work fast to keep up," says Susan. "Unlike other publishers, Mills & Boon read all manuscripts they receive, not just those supplied by agents, and the Romantic Novelists Association runs a new writers scheme and courses."

Mills & Boon has pioneered opportunities in digital publishing and was one of the first publishers to embrace ebooks, offering more than 17,000 backlist titles and all its front list in digital. Today Mills & Boon is a division of HarperCollins UK.

Susan relishes the supportive network of romance writers worldwide. "I get up at 5am and start writing, I'm very strict with myself. Writing is such a lonely occupation; it's helpful have contact with other writers online.

"People are quick to scorn commercial romantic fiction but we reach women across the world - my books are translated into many languages, including Greek and Hebrew - and being a Mills & Boon writer has allowed me to travel and meet other authors around the world; people I'd never normally meet.

"I feel incredibly lucky to make a living from doing what I love most."

* A Sheikh's Service, published by Mills & Boon in paperback and ebook priced £3.99, is available at millsandboon.co.uk