As the villain-hero of Shakespeare's play, Macbeth has displayed from the onset a bravery that has wavered only with his first act of murder, the regicide of King Duncan and the appearance of Banquo's ghost. Otherwise, Macbeth is bold and merciless against his enemies. Before his encounter with the three witches which changes his course in life, Macbeth displays much valor in battle. In Act I, the Captain extols the merits of the warrior Macbeth:
For brave Macbeth--well he deserves that name--
Disdaining fortune, with his brandished steel,
Which smoked with bloody execution,
Like valor's minion carved out his passage (1.2.16-21)
Then, in Act V, Macbeth, true to his warrior nature, remains confident of surviving the battle with Malcolm's army despite his own troops' desertion. For, he feels his castle will withstand any attack:
....Our castle's strength
Will laugh a siege to scorn. Here let them lie
Till famine and the ague eat them up. (5.5.2-4)
Later, when the messenger informs Macbeth that Birnam Wood is moving toward the castle, he realizes that the predictions of the witches has come true. So, he tells Macduff that he will not fight with him. But when Macduff calls him a coward and tells him to yield, Macbeth, proud and brave to the end, resolves to fight even if he will be killed,
I will not yield.
To kiss the ground before your Malcolm's feet.
Though Birnam Wood be come to Dunsinane....
Yet I will try the last. (5.8.28-31)
Issuing a challenge to Macduff, Macbeth throws his "warlike shield" before him and begins to battle his foe, who is "not born of woman."