Shakespeare only ever wrote two plays with original plots: Love’s Labor’s Lost and The Tempest. For all his other works he borrowed plots from other writers, often re-ordering events, inserting subplots, and adding or removing characters. The book he relied on most heavily for plot ideas was Holinshed’s Chronicles. Published in 1577, the Chronicles is a collaborative work written by Raphael Holinshed and others. The volume includes histories of England, Scotland, and Ireland from the earliest time of inhabitation to the mid-sixteenth century. The Chronicles served as Shakespeare’s source for nearly all of his history plays. The plot of Macbeth also came from the Chronicles, as did plot elements for King Lear and Cymbeline. Shakespeare’s second most important source was a book by the Roman historian Plutarch, titled Lives of the Noble Greeks and Romans. Shakespeare may have read the book in the original Latin, but he definitely read Thomas North’s English-language translation. We know this because Shakespeare clearly based Julius Caesar,Antony and Cleopatra,Coriolanus, and Timon of Athens on North’s translation. Indeed, sometimes Shakespeare followed North’s wording so closely that a reader can figure out which page of Lives he drew on for particular scenes.
Aside from these major works, Shakespeare also borrowed from dozens of other writers. He borrowed many plot ideas from Italian writers, especially from a medieval collection of stories called The Decameron, by Giovanni Boccaccio. He also borrowed from Roman writers, especially Ovid, Seneca, and Plautus, and from the great medieval English poets Geoffrey Chaucer and John Gower. He even updated stories that had been popular just a few decades earlier. For instance, The Winter’s Tale (written around 1609) was based on a much-loved narrative published in 1588 by Robert Greene, and Romeo and Juliet (written around 1595) is closely based on a long narrative poem by Arthur Brooke that was popular in the 1560s. Shakespeare also occasionally drew inspiration from current events. Although the plot of The Tempest (written around 1610) has no precursor, Shakespeare based the catastrophic storm that opens the play on accounts of a shipwreck that occurred in Bermuda in 1609. He also interwove thematic elements from works by his contemporary Ben Jonson, the Roman poet Ovid, and the French essayist Michel de Montaigne.