Macbeth, General of war of King Duncan from Scotland, was very much appreciated in the court by his skills in the combats:
"SCENE II. A camp near Forres.
Alarum within. Enter DUNCAN, MALCOLM, DONALBAIN, LENNOX, with Attendants, meeting a bleeding Sergeant
DUNCAN
What bloody man is that? He can report,
As seemeth by his plight, of the revolt
The newest state.
MALCOLM
This is the sergeant
Who like a good and hardy soldier fought
'Gainst my captivity. Hail, brave friend!
Say to the king the knowledge of the broil
As thou didst leave it."
One day, back from a victorious battle, accompanied by his friend Banquo, he is surprised by three witches with the next prophecies: Macbeth would be Thane of Cawdor and king of Scotland, and the descendants of Banquo would inherit the crown. The witches vanish on air, leaving the two characters thinking about the foresight of the supernatural power.
Surprisingly, a messenger of the king informs him about his nomination as Cawdor's Thane, making true so, one of the prophecies of the witches. In view of that, Macbeth glimpses the very position of reign, which dominates his soul and brings his perdition.
So, seized by a deep and furious sense of ambition and encouraged by Lady Macbeth, wife ruled by the same vile values, Macbeth kills the king Duncan, in search of the possession of the crown:
SCENE V. Inverness. Macbeth's castle.
Enter LADY MACBETH, reading a letter
(...)
MACBETH
My dearest love,
Duncan comes here to-night.
LADY MACBETH
And when goes hence?
MACBETH
To-morrow, as he purposes.LADY MACBETH
O, never
Shall sun that morrow see!
Your face, my thane, is as a book where men
May read strange matters. To beguile the time,
Look like the time; bear welcome in your eye,
Your hand, your tongue: look like the innocent flower,
But be the serpent under't. He that's coming
Must be provided for: and you shall put
This night's great business into my dispatch;
Which shall to all our nights and days to come
Give solely sovereign sway and masterdom.