Agatha Christie is the most-translated fiction author in the world, according to the UNESCO. Her work has been translated into more than 70 languages. It is often said that she is outsold only by the Bible and Shakespeare.

According to the Guinness Book of Records, Agatha Christie is the best-selling fiction author of all time with an estimated two billion copies of her books in print. By comparison, around 270 million copies of J.K. Rowling's Harry Potter books have been sold.

She wrote 80 novels and short story collections and 19 plays. She also wrote two books of poetry, a children's book, and two autobiographical works.

Agatha penned six romance novels under the name of Mary Westmacott. This pseudonym remained a secret for almost 20 years until her nom de plume was revealed by the Sunday Times.

Her most famous play, The Mousetrap, is the longest continuously running play of all time, according to the Guinness Book of World Records. It opened at the Ambassadors Theatre in London on November 25, 1952. It moved next door to the St. Martin's Theatre on March 25, 1974, not missing a single performance. It continues to this day. It was originally written as a 20-minute radio drama, commissioned by the BBC to celebrate the 80th birthday of Queen Mary.

Profits from the production go towards the Mousetrap Foundation, which provides of opportunities for young people from all over the UK to come to the theatre at reduced prices.

The author presented the rights to The Mousetrap to her grandson Mathew Prichard for his ninth birthday but a toy train made "much more of an impression" at the time.

She once had three plays running simultaneously in London's West End – an unrivalled feat.

Her most popular characters are the portly Belgian detective Hercule Poirot and the spinster sleuth Jane Marple. Poirot features in 33 novels and 54 short stories. There are 12 Marple novels and 20 short stories.

Her first book was written as a result of a bet. Her sister Madge wagered Agatha that writing a detective novel would be too difficult a task.

The resulting novel, The Mysterious Affair at Styles, was written in 1916 in the down time while working in a hospital dispensary in Torquay. But it took five years to find a publisher. The manuscript was sent to several publishers before it was eventually accepted by the Bodley Head in 1920.

Agatha married Archie Christie, a young pilot who became a war hero, in 1914. Her only daughter, Rosalind, was born five years later. But it was not a happy marriage, and Archie's infidelity caused Agatha great unhappiness. The couple divorced in 1928.

She remarried in 1930 to archaeologist Max Mallowan. They remained happily married until Agatha's death in 1976.

Between 1930 and 1958 Agatha spent most of her winters in Iraq and Syria, assisting her husband Max Mallowan on his archaeological digs. Come Tell Me How You Live is her delightful autobiographical account of this other life she led. Many of famous adventures, including Death on the Nile and Murder on the Orient Express, were informed by her regular visits to the Middle East.

In 1917, aged 24, she qualified as a dispensing chemist thus acquiring a useful knowledge of poisons.

Agatha never went to school. She was educated at home by a succession of governesses.

In her teens she studied to be a classical musician but had to give it up because of stage fright.

Agatha was passionate about music. Her favorite composers were Elgar, Sibelius and Wagner.

It is often – mistakenly – assumed that Agatha based the character of Marple upon herself. In her autobiography, however, she explains: "Miss Marple is the sort of old lady who would have been rather like some of my grandmother's Ealing cronies – old ladies whom I have met in so many villages where I have gone to stay as a girl. Miss Marple is not in any way a picture of my grandmother; she is far more fussy and spinsterish than my grandmother ever is. But one thing she did have in common with her - though a cheerful person, she always expected the worst of everyone and everything, and is, with almost frightening accuracy, usually proved right."

And Then There Were None is her bestselling novel around the world. The original title Ten Little Niggers carries potentially offensive connotations today that it didn’t on original publication and that Agatha Christie never intended in the original. Agatha Christie Ltd therefore made the decision to use the title And Then There Were None - under which this novel was actually first published in the USA in 1940, in order to avoid causing any potential offence and to maintain consistency worldwide.

She described The Mystery of the Blue Train as "easily the worst book I ever wrote". Of her own work, her favorite play was Witness for the Prosecution, later turned into a film starring Charles Laughton and Marlene Dietrich.

Death Comes as the End, set in ancient Egypt, is Agatha's only attempt at historical fiction. Its genesis came from a suggestion by Egyptologist Stephen RK Glanville.

In her prime Agatha was rarely out of the bestseller lists. Her British publishers actively marketed the availability each year of a "Christie for Christmas".

She accepted the presidency of the famous Detection Club in 1958 on the strict understanding that she would never have to make a speech.

She continues to be adapted to new mediums. A North American firm has developed a computer game based on And Then There Were None. Visit Agatha Christie: "And Then There Were None"