Who is William Shakespeare, from from The Sandman and what is their importance?

William Shakespeare is admittedly a brilliant playwright. Even the fairy folk, who seem to look down on human beings, admire Shakespeare's writing in "A Midsummer Night's Dream." His greatest desire is to have his plays live on beyond him and to achieve great fame as a playwright. Because of his ambition, he has made a deal with the Sandman that his plays will live on in greatness in exchange for writing two plays for the supernatural king of dreams. Because the reader has knowledge of the historic William Shakespeare, the reader knows that his ambitions will come true. This creates a kind of dramatic irony in the story, because the reader has foreknowledge that the characters lack.