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, and took the throne for himself. Denmark has a long-standing feud with neighbouring Norway, in which King Hamlet slew King Fortinbras of Norway in a battle some years ago. Although Denmark defeated Norway and the Norwegian throne fell to King Fortinbras's infirm brother, Denmark fears that an invasion led by the dead Norwegian king's son, Prince Fortinbras, is imminent.On a cold night on the ramparts of Elsinore, the Danish royal castle, the sentries Bernardo and Marcellus discuss a ghost resembling the late King Hamlet which they have recently seen, and bring Prince Hamlet's friend Horatio as a witness. After the ghost appears again, the three vow to tell Prince Hamlet what they have witnessed.