The protagonist of Hamlet is Prince Hamlet of Denmark, son of the recently deceased King Hamlet, and nephew of King Claudius, his father's brother and successor. Claudius hastily married King Hamlet's widow, Gertrude, Hamlet's mother. Denmark has a long-standing feud with neighbouring Norway, and an invasion led by the Norwegian prince, Fortinbras, is expected.
The play opens on a cold winter midnight on "a platform before the castle" of Elsinore, the Danish royal castle. The sentries Bernardo and Marcellus and Hamlet's friend Horatio encounter a ghost that looks like the late King Hamlet. When it declines to talk to them they attack it with daggers, but it escapes. Marcellus admits: "We do it wrong... to offer it the show of violence / For it is... invulnerable." They vow to tell Prince Hamlet that his father's ghost has been seen.
