Short answers, pulled from the story.
William Shakespeare wrote Hamlet sometime between 1599 and 1601. Scholars offer dates ranging from 1599 or 1600 to mid-1601, and the play is not listed among the twelve Shakespeare plays named in Francis Meres's 1598 Palladis Tamia, suggesting it had not yet been written.
Hamlet is set in Denmark and follows Prince Hamlet as he tries to avenge his father, who was murdered by his uncle Claudius. Claudius seized the throne and married Hamlet's mother Gertrude, and the play ends with Gertrude, Laertes, Claudius, and Hamlet all dead, with Hamlet naming Fortinbras as his successor.
Hamlet is by far the longest play Shakespeare wrote and one of the longest in the Western canon. The Second Quarto of 1604 contains 28,628 words and the First Folio 27,602, and a full staging might require more than four hours, compared with the two to three hours of a typical Elizabethan play.
Three early versions of Hamlet survive: the First Quarto of 1603, the Second Quarto of 1604, and the First Folio of 1623. Each includes lines and passages missing from the others, and the First Quarto contains just over half the text of the Second Quarto.
Possible sources for Hamlet include the Scandinavian Saga of Hrolf Kraki, the Roman legend of Brutus, and the 13th-century Life of Amleth by Saxo Grammaticus, which Francois de Belleforest translated into French in 1570. One theory holds that Shakespeare's main source was a lost play known today as the Ur-Hamlet, which would have existed by 1589.
Sigmund Freud read Hamlet through the Oedipus complex, first writing about it in The Interpretation of Dreams in 1899. He argued the play is based on Hamlet's hesitation to take revenge because Claudius had realized Hamlet's own repressed childhood desires, and he once considered naming the idea the Hamlet complex.
Shakespeare almost certainly wrote the role of Hamlet for Richard Burbage, the chief tragedian of the Lord Chamberlain's Men. Sarah Siddons was the first actress known to play him, and Lewis Hallam Jr. became the first known to play Hamlet in North America, in Philadelphia in 1759.