The Blagger's Guide To: Agatha Christie

The queen of crime who did her best thinking in the bath

As ITV announces plans for its sixth series of Agatha Christie's Marple, a new book offers an exhaustive account of the world's third best-selling author written by a true fanatic. Cathy Cook's The Agatha Christie Miscellany offers biographies of Christie, Poirot, Miss Marple and other characters, details of the author's favourite foods, a comparison of the various theories surrounding her 1926 disappearance, and "10 rules" for solving the mysteries, as well as many more geeky details.

Agatha Mary Clarissa Miller was born on 15 September 1890 in Torquay. Her parents were Clarissa Margaret and Frederick Alvah Miller: "Gentleman". Rudyard Kipling and Henry James both came to tea at her childhood home. Christie never went to school and was home educated by her mother. During the First World War she volunteered at a hospital in Torquay, where she worked in the dispensary, learning about medicines and poisons.

Poison is the most common murder weapon in Christie's novels – the most dangerous rooms being the bedroom, library, and study. Her first novel, The Mysterious Affair at Styles, was reviewed by the Pharmaceutical Journal, which wrote admiringly: "This novel has the rare merit of being correctly written." Many real-life crimes have been inspired and informed by Christie's works. In 1977 in France, a killer admitted to using atropine to poison a bottle of red wine after reading about it in The Tuesday Club Murder. In 2009, Iran's first female serial killer claimed that she had taken tips from Christie's novels. However, in 1975 a baby was saved from thallium poisoning because a nurse was reading The Pale Horse and recognised the symptoms from the plot.

The butler did it in only one Christie novel.

Although Christie steered clear of basing characters on people from real life, her second husband, the archaeologist Max Mallowan, featured in Murder in Mesopotamia as a thoroughly decent minor character called David Emmott. Mallowan said that Christie's most autobiographical novel was Unfinished Portrait, in which the lead character, Celia, splits with her husband after he becomes obsessed with golf – as did Christie from her first husband, Archibald.

Hercule Poirot (played on television by David Suchet) was already in his sixties in his first appearance in the 1920's. He was presumably about 120 by the time he died in Curtain, published in 1975. He was the only fictional character ever to receive an obituary in The New York Times. Owing to his popularity, Christie kept writing Poirot mysteries, even though by 1930 she found him "insufferable" and in 1960 she called him a "detestable, bombastic, tiresome, ego-centric little creep".

Shortly before writing Murder on the Orient Express, Christie slipped on an icy platform and fell underneath the actual train, which was stationary in Calais. A quick-thinking railway porter pulled her off the rails just before the train started moving.

Christie said she did her best thinking while lying in the bath, eating apples and drinking tea. She claimed that modern baths weren't made with authors in mind as they were "too slippery, with no nice wooden ledge to rest pencils and paper on".

The Agatha Christie Miscellany by Cathy Cook (The History Press, £9.99) is published tomorrow.