The world's bestselling authors have made their mark on literature with millions, even billions, of books sold. 

Famous playwrights like William Shakespeare to mystery novel writers like Agatha Christie and children's book authors such as Dr. Seuss are among the bestselling authors of all time, proving one specific genre isn't more successful than the rest. 

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Take a look below at five of the bestselling authors in history — and the books that helped them reach their standing. 

The English poet, playwright and actor William Shakespeare is the bestselling author of all time. 

There have been between 2 billion and 4 billion copies of Shakespeare's works sold. 

Born in April 1594, Shakespeare began his writing career in London. His first two printed works were long poems titled "Venus and Adonis" in 1593 and "The Rape of Lucrece" in 1594. 

The Renaissance Era writer penned at least 38 plays, two narrative poems and 154 sonnets. There are no original manuscripts known to exist to this day, according to the Shakespeare Birthplace Trust website. 

Shakespeare was a member of Lord Chamberlain's Men, an acting company in London that later became The King's Men. 

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Shakespeare also built the Globe Theater. A third version of the theater stands today. 

Popular plays written by Shakespeare include "The Merchant of Venice," "Romeo and Juliet," "Othello," "Twelfth Night," "Hamlet," "Macbeth" and "A Midsummer Night's Dream." 

Agatha Christie, dubbed the "Queen of Mystery," wrote 66 detective novels and 14 short story collections in her life.  

There have been over 2 billion copies of Christie's books sold. 

Christie was born in Sept. 1890 in Torquay, United Kingdom. The first book she ever published was "The Mysterious Affair at Styles" in 1920. 

Popular books of Christie's include "Murder on the Orient Express" and "The Murder of Roger Ackroyd." 

She also wrote the play "The Mousetrap." The work is the world's longest running play, according to the author's website. 

It currently runs in London's West End. 

Over 1 billion copies of Danielle Steel's books have been sold. 

All of her books published have been bestsellers, according to the author's website. 

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She has written over 210 books, according to her own website, 182 of which are novels. Her newest novel, "Only the Brave," was published in April 2024. 

She has also penned 18 children's books and four nonfiction books, though she's best known for her romance novels. 

Harold Robbins wrote over 25 bestselling books.

The first was "Never Love a Stranger." Over 750 million copies of his books have sold.

Born May 21, 1916, Robbins wrote many novels turned into movies, including his first. 

Other books by Robbins that were turned into movies include "Stiletto," "Where Love Has Gone," "The Betsy" and "The Lonely Lady." 

In 1971, a documentary was released about his life, "I'm the World's Best Writer-There's Nothing More to Say." 

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Robbins' last published novel was "Tycoon," which was released in 1997. Robbins died on Oct. 14, 1997.  

Dr. Seuss was a children's author whose books have been beloved by generations. 

Dr. Seuss, whose real name is Theodor Seuss Geisel, was born on March 2, 1904, in Springfield, Massachusetts. 

He studied at Dartmouth College, where he earned a bachelor of arts in English. 

His first children's book, "And To Think That I Saw It on Mulberry Street," was published in 1937. From there, he published over 60 books that have sold over 700 million copies. 

"Horton Hears a Who!," "The Cat in the Hat," "How the Grinch Stole Christmas," "Green Eggs and Ham," "One Fish Two Fish Red Fish Blue Fish," "The Lorax" and "Oh, the Places You'll Go!" are all among popular books written by Seuss. 

Many, like "Horton Hears a Who!" and "How the Grinch Stole Christmas," have been made into movies.  

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