Shakespeare is renowned for beginning his plays in medias res, using the backdrop of impending war (Hamlet) and bloody battle (Macbeth).
Shakespeare uses cacophony (discordant language and imagery) by his characters to set a mysterious and threatening tone. Just listen to the meek scholar Horatio's war imagery:
Was, as you know, by Fortinbras of Norway,
Thereto prick'd on by a most emulate pride,
Dared to the combat; in which our valiant Hamlet--
For so this side of our known world esteem'd him--
Did slay this Fortinbras;
Not only is there a literal, physical threat of war in the opening scene, but there will be a spiritual battle later in the act waged by the Ghost, who apears in full armor, as if in a battle. Indeed, the Ghost is in Purgatory, battling for his soul. And he is a Revenge Ghost, summoning his meek son to kill a well-guarded king. As such, he must motivate by using war-like language later in the act.
All of these fighting words are either alluding to past wars or foreshadowing the impending wars between:
- Denmark vs. Norway
- Fortinbras vs. Claudius
- Hamlet vs. Claudius
- Claudius vs. King Hamlet
- Hamlet vs. women (Gertrude and Ophelia)
- Sanity vs. Insanity
- Revenge vs. Forgiveness
- Hamlet vs. Polonius' family (especially Laertes)
- Hamlet vs. himself
- The supernatural (Ghost) vs. the natural (Hamlet) vs. the unnatural (Claudius's regicide and Claudius' & Gertrude's incest
Horatio answers Barnardo's questions about the preparations for war by telling him that years ago, King Hamlet and the king of Norway entered into combat. King Hamlet won and, as decreed by law and a sealed compact, won the King Fortinbras' lands. Now, the son of the now-deceased king of Norway, Young Fortinbras, is gathering a group of mercenaries to go to battle against Denmark and retrieve those lands lost by his father. In anticipation of that conflict, Denmark's war implement manufacturers are working around the clock. To add to this warlike setting, when the ghost of King Hamlet appears, he is wearing his war helmet that he wore when he battled King Fortinbras of Norway, (1.1 lines 83-111). All of this talk of war and the ghost's warlike appearance lend to the dark and menacing atmosphere of this tragedy. It lets the audience know that this is a serious play and the physical war parallels the internal war that goes on inside of Hamlet all through the play to the final scene. Hamlet struggles with his emotions and his lack of action.