Final answer:
King Duncan decides to make Macbeth Thane of Cawdor due to Macbeth's loyalty, bravery, and recent victory in battle. It's also a strategic move to strengthen their alliance and prevent potential rebellion.
Step-by-step explanation:
King Duncan decides to make Macbeth Thane of Cawdor because the previous Thane of Cawdor has betrayed him. In Act 1, Duncan learns that the Thane of Cawdor has been executed for treason. This opens up the position, and Duncan sees Macbeth's loyalty and bravery in battle as qualities that make him deserving of the title.
It also serves as a reward for Macbeth's recent victory in battle where he defeated the rebels led by the former Thane of Cawdor.
Furthermore, Duncan may see Macbeth's new title as a way to strengthen his alliance with Macbeth and secure his loyalty.
By giving Macbeth the title of Thane of Cawdor, Duncan is showing trust in him and is essentially making him a part of the royal court. This move may help Duncan maintain a sense of unity among the nobility and prevent any potential rebellion against his rule.
Overall, King Duncan decides to make Macbeth Thane of Cawdor because he sees Macbeth's loyalty, bravery, and recent victory in battle as qualities that make him deserving of the title. It's also a strategic move to strengthen his alliance with Macbeth and prevent potential rebellion.