Who delivers a message to King Duncan and what news does he bring?

A messenger, a sergeant returning from battle, delivers a message to King Duncan. He informs the king about the brave actions of Macbeth and Banquo in defeating the rebel forces, particularly highlighting Macbeth's valor in battle. This news leads Duncan to decide to reward Macbeth for his bravery by granting him the title of Thane of Cawdor.