Who are the first characters you meet in hamlet?

The first characters you meet in Shakespeare's "Hamlet" are the sentinels Francisco and Barnardo, along with Horatio, who is a friend of Prince Hamlet. They are on guard at Elsinore Castle and discuss the appearance of a ghost resembling the deceased King Hamlet. Their conversation sets the tone for the play, introducing themes of uncertainty and foreboding. Hamlet himself is not introduced until later in the first act.