Probably one of the best known is 1984 author George Orwell. His name was apparently inspired in part by the River Orwell and the George was chosen because it was very British. As for the reason, it is generally thought that he chose to use a pseudonym because he was frightened of failure. On using a pen name, he said: “I suppose the thing is to have an easily memorable one – which I could stick to if this book had any success.”

Many female authors would use male pen names to ensure they would be taken more seriously, and Mary Ann Evans was no different. She also did it to avoid the stereotype of women expected to write romance novels as well as the fact she was trying to prevent her private life from being exposed, as she had been in a relationship with a married man for over 20 years.

Allof the Brontë sisters were told to change their names by a male publisher as apparently they wouldn't be published otherwise. However, it was a poorly guarded secret and even early reviewers of "Currer's" work outed "him" as a woman. In 1850 Charlotte Brontë wrote: "we had a vague impression that authoresses are liable to be looked on with prejudice".

Already a successful author, King adopted the name Richard Bachman to see if it was talent or luck that made him a famous writer. He also deliberately released the Bachman novels with as little marketing presence as possible. While the Bachman book Thinner sold 28,000 copies during its initial run in 1984, it then sold ten times as many when it was revealed that Bachman was, in fact, King.

Best known for writing The Chronicles of Narnia, C. S. Lewis used two different pseudonyms for different reasons. He published a collection of poems, Spirits in Bondage, and a narrative poem, Dymer, under the pen name Clive Hamilton to avoid harming his reputation as a don at Oxford University. His book entitled A Grief Observed, which describes his experience of bereavement, was originally released under the pseudonym N. W. Clerk.

Agatha Christie was already a successful writer of crime novels but she wanted a break from that so she could define an 'alter ego' and to write more for fun. In 1950, when she was invited to a celebration for her work, she quipped, "Thank you for asking me to meet Agatha Christie. If you don't mind, I am bringing my old friend Mary Westmacott with me."

Washington Irving, most famous for writing Sleepy Hollow, released his debut under the name Jonathan Oldstyle, in 1802. In 1809, he finished his first long book "A History of New-York from the Beginning of the World to the End of the Dutch Dynasty'' published under the pen name, Diedrich Knickerbocker. However, before its publication, he began a marketing hoax by publishing missing person notices in New York newspapers asking about Knickerbocker, saying he was a Dutch historian, who had gone missing from his hotel in New York City. As a result, when it was eventually published, it was very popular.

The Harry Potter author used initials (even though she has no middle name) to ensure there was no bias on grounds of gender and her books would appeal to both sexes equally. Last year, she also published a novel under the name Robert Galbraith to see whether her new book post-Harry would be well received. The author has recently announced that she will be writing her new novel under the Galbraith name again.

Like many other writers in this list, Nora Roberts was a popular author before she ever used the pen name J.D. Robb. She was the author of romance novels, of which she had already published around 200, but as she wanted to write detective novels, she wrote them under a more male-sounding name.

The woman who created one of the most popular erotic book series ever was originally known as Snowqueens Icedragon, when she began writing Fifty Shades of Grey as part of Twilight fan fiction, Master of the Universe. Despite the fact she got positive reviews, apparently, the controversial sexual nature of the material meant James had to take down the material and publish it on her own site.

Unlike the other pseudonyms on this list, Lemony Snicket actually appears in the books he has written, as an author and sometimes character, so that the reader would never really know if it was the author's real name or pen name.

After studying as a steamboat pilot, for which Twain studied 2,000 miles of the Mississippi for over two years before receiving his license in 1859, Twain discovered his pen name: it comes from "mark twain," the cry for a measured river depth of two fathoms.

The Bell Jar came out in January 1963 and was published under the pen name Victoria Lucas. The reason why Plath used a pen name was because apparently she never wanted her mother to know she written the book for fear of upsetting her, and any other people who she'd featured in the novel.

The Alice's Adventures in Wonderland author was known to be modest and as a scholar and instructor at Oxford, he valued his privacy, so much so he would refuse letters sent to Lewis Carroll.

Unknown to most people, Louisa May Alcott had been publishing poems, short stories, and thrillers since 1851, under the pen name Flora Fairfield. In 1862, she also adopted the pen name A.M. Barnard, and some of her melodramas were produced on Boston stages.