Image caption There will be bonnets: Period costumes form an important part of Jane Austen fan events

It has one of the most famous opening lines in literature, it turned Colin Firth into a heartthrob and it spawned a zombie spin-off. Now Pride and Prejudice has reached the venerable age of 200.

It is a truth universally acknowledged that the bicentenary of Pride and Prejudice will be accompanied by a surge of Jane Austen-related events and merchandise - and articles that shamelessly hijack the novel's first sentence.

Monday's anniversary is being marked by a "readathon" of the novel at the Jane Austen Centre in Bath, which has launched an 11th-hour internet campaign to find an international star to read the first chapter.

Experts, writers and fans will read the entire novel in a 12-hour internet broadcast, which will hook up with Jane Austen societies in Australia and North America. Jane Austen societies also exist in Japan, the Netherlands and Brazil.

Jane Austen Jane Austen (1775-1817) was one of eight children in a close-knit family

Born on 16 December 1775 in the village of Steventon in Hampshire

In 1801 the family moved to Bath

After the death of her father, the family moved several times, eventually settling in Chawton, Hampshire

Her brother Henry negotiated with a publisher for her first novel, Sense and Sensibility

She described her next, Pride and Prejudice, as her "own darling child"

In 1816 Austen began to suffer from ill-health, thought to be Addison's disease. She died in Winchester a year later, aged 41

Her legacy was six celebrated novels, which offered insight into the lives of middle- and upper-class women in the early 19th Century Source: BBC History See an Austen handwritten manuscript View paintings held by Jane Austen's house

"It's a worldwide industry," says Jane Austen Centre spokesman David Lassman. "There's always been an audience, but the BBC production in 1995 was the turning point that sent Jane Austen global.

"At the heart is the six books, but she is a brand and there's no getting away from that."

The Jane Austen Centre has about 60,000 visitors per year, and an estimated 80% of them are women. Dressing in period costume is a key part of the annual Jane Austen Festival in Bath, where the writer lived from 1801 to 1806.

"Bath retains much of architecture from that time, so people come from all round the world to dress up and literally walk in the footsteps of Jane Austen and see the same buildings she saw," says Mr Lassman.

"The audience is predominantly female. We do find that boyfriends or husbands are brought along kicking and screaming - often in military uniform - but in the end they seem to enjoy it."

'Darling child'

First published by Thomas Egerton in 1813, Pride and Prejudice was Jane Austen's second novel. She described it as her "own darling child".

Although out of copyright and available for free on e-readers, it is estimated that the book - with the relationship between Elizabeth Bennet and Mr Darcy at its heart - sells up to 50,000 copies each year in the UK.

"The book didn't catch on quite as quickly as you'd expect - the third edition was remaindered," says Professor Janet Todd, the general editor of the nine-volume Cambridge edition of the works of Jane Austen.

"It is the only one of Austen's novels that really captures that popular romance story of a girl catching an upper-class male with money. An arrogant man is brought down by love.

"It's the romantic story that you get in Daphne du Maurier and Mills and Boon. Nobody else quite does this, and no other book of Jane Austen's does it either."

Professor Todd, who is organising a conference at Cambridge University's Lucy Cavendish College in June to mark the bicentenary of Pride and Prejudice, describes the novel as "much sunnier" than Austen's other works. "It's also very simple and very complex - you can't say that of most books."

The conference will explore the original historical context of the novel, as well as the numerous screen adaptations and literary spin-offs the book has inspired.

Image caption Colin Firth as Mr Darcy and Jennifer Ehle as Elizabeth Bennet in Pride and Prejudice (BBC 1995)

As well as the BBC's 1995 TV version, starring Colin Firth as Darcy and Jennifer Ehle as Elizabeth, Pride and Prejudice was rejuvenated on the big screen in 2005 in Joe Wright's film starring Matthew McFadyen and Keira Knightley. It took more than £76 million at the global box office.

Firth revisited the Darcy persona in Bridget Jones's Diary (2001), which was loosely based on the Austen story. Meanwhile, Gurinder Chadha's 2004 film Bride And Prejudice gave it a Bollywood-style spin.

What's the enduring appeal of Pride and Prejudice? "It can be read on so many levels," says Marilyn Joice, a committee member of the Jane Austen Society of the UK. "You can read it as a romantic Cinderella story, a comedy or as a social commentary on the problems facing women of Austen's own social strata. "It's expressed with some biting, often very subtle irony, so you don't need to be an academic to get something out of it. "Most people love a happy ending and Pride and Prejudice does seem to offer that at least for some of the characters. "One of the things I personally like about Austen is that she doesn't lay it out for you. She demands that you read between the lines. She's an author who says, 'I think my readers are intelligent.' "I must have read Pride and Prejudice up to 10 times - every time I go back to it, I still find myself laughing because the comic characters are really well-drawn. It's fresh for me every time I read it." Jane Austen Society of the UK

Older adaptations include the 1940 film - co-written by Brave New World author Aldous Huxley - starring Greer Garson as Elizabeth and Laurence Olivier as Darcy.

Dr Shelley Cobb, of the University of Southampton, says some of the key academic debates are about how the Jane Austen adaptations link to contemporary ideas about feminism.

"The debates about Austen's feminism have been going on since the late 1970s, and contemporary adaptations regularly suggest she is a proto-feminist," says Dr Cobb, who will be speaking on the subject at a Pride and Prejudice study day at Chawton House Library in Hampshire on 9 February.

"Adaptation is interesting because it is always responding to the original novel and the way that we understand things now," she adds.

When Colin Firth's Mr Darcy emerged from the lake in the BBC TV adaptation it was a moment that highlighted the way that adaptation was made for female viewers, says Dr Cobb.

"It's a moment that's become so well known. Colin Firth as Darcy is clearly meant to be looked at and admired by female viewers, and that is played out in Bridget Jones. It's become a post-modern joke by the time of the ITV series Lost in Austen."

Other novel twists on the story include crime writer PD James's Death Comes to Pemberley (2011), a sequel that thrusts Elizabeth Bennet and Mr Darcy into a murder mystery, and Seth Grahame-Smith's 2009 literary "mash-up" Pride And Prejudice And Zombies.

The latter opens with a line that might make Jane Austen not only turn in her grave, but also crawl out of it with her arms out-stretched: "It is a truth universally acknowledged that a zombie in possession of brains must be in want of more brains."

Image caption Jerusha Hess's Austenland stars Keri Russell (left) as a woman obsessed with Jane Austen's Pride and Prejudice

Just premiered at the Sundance Film Festival is Austenland, a film about a Jane Austen devotee - she owns a life-size cut-out of Colin Firth - who blows her life savings to visit a Jane Austen theme park in the UK.

Directed by Jerusha Hess, Austenland has a mainly British cast and crew and was filmed on location in the UK. The film's producer is Twilight author Stephenie Meyer, who knows a thing or two about obsessive fans.

Last year saw the launch of The Lizzie Bennet Diaries, a modernised adaptation of Pride and Prejudice that unfolds through video blogs and social media.

Lizzie Bennet, played by Ashley Clements, is a 24-year-old mass communications student, while other characters include college boys Bing Lee and William Darcy. The main story thread has reached 80 episodes and counting.

Image caption Ashley Clements plays the lead role in the Lizzie Bennet Diaries

Other Pride and Prejudice anniversary events include an exhibition at Jane Austen's House Museum in Chawton, which includes the letter Jane wrote to her sister Cassandra on first receiving her copy of the book.

The BBC is recreating a Regency-era ball in Pride and Prejudice: Having a Ball on BBC Two at Easter. The programme will examine the social history of Austen's world and show how such social events helped women find a husband.

And the University of Hertfordshire is hosting The Locations of Austen, a conference (running from 11 to 13 July) to consider how Jane Austen's fiction relates to the landscape.

With so many avenues already explored, do we know all there is to know about Jane Austen?

"Austen is quite like Shakespeare in that there's always something new to say," says Dr Cobb.

"Every generation reinterprets and responds to her in their own way. And with the little we know about Jane Austen's life we're always trying to figure out what she was really like - that mystery element always keeps us going."

Professor Todd says that one key to the longevity of Jane Austen work is that "she didn't write for people who can't think".

"I don't think she wanted to write a book that is simply borrowed from the library and then taken back or a paperback that's thrown away, She wanted to write books that people valued, kept and read."