Pseudonyms Used by Best-Selling Authors

Robert Galbraith's debut novel The Cuckoo's Calling already received rave reviews, but when it was revealed that the author was actually J.K. Rowling of Harry Potter fame, it instantly jumped to the top of bestseller lists. 

This is not the first time a popular writer has used a pseudonym for other works.  Stephen King is a famous example when he wrote a series of thrillers under the nom de plum Richard Bachman until finally being outed. The Bachman books are interesting curiousities, having some obvious examples of the King style, but also having their own distinctive voice.

Some writers use an alias for practical reasons, such as to take a stab at a different genre, or to try to make inroads into a publishing industry that might be dominated by a specific gender.  Both these reasons apply to Rowling. Best known for her fantasy saga, her new book is a murder mystery. Maybe she wanted to see how it would do without the baggage of her famous name, contrasted with her previous attempt to branch out beyond the adventures of the boy wizard, The Casual Vacancy. Her real name is Joanne "Jo" Rowling, and she decided to use the initials "J.K." on the advice of her publisher, because it was thought that the audience for the Harry Potter series would be predominantly young boys and maybe they might not pick up a book written by a woman.  Such silly market-driven naming games have been happening for a long time -- other examples include Louisa May Alcott who wrote as A.M. Barnard, Mary Ann Evans as George Eliot, Charlotte Bronte as Currer Bell, and Emily Bronte as Ellis Bell.  Other female writers who used ambiguous initials instead of full first names to "hide" their sex are V.C. Andrews and D.C. Fontana.

Some literary masters have been better known in history by their pen names instead of their birth names.  Samuel Clemens and Charles Dodgson immediately come to mind, better known respectively as Mark Twain and Lewis Carroll.

Another popular writer who falls into the Stephen King and J.K. Rowling category of established, successful authors who decided to write new books under identity-masking aliases is Nora Roberts who dabbled in sci-fi-ish detective fiction as J.D. Robb.

Let me know if you can think of any others.  What do you think of the rationale for doing so?