In William Shakespeare's Macbeth, King Duncan of Scotland is kind and well-respected. He is a fair and generous leader. His generosity is evident several times in the play.
Pleased with Macbeth's success in defeating the rebels and the Norwegian army, Duncan sends messengers to thank Macbeth for his bravery and service, and to inform him that the king has granted him the title of Thane of Cawdor (the previous and treacherous title holder having been captured and awaiting execution).
Duncan instructs the messengers to bring Macbeth and Banquo to him, so that he may praise them in person. The king personally thanks Macbeth and Banquo profusely for their service and tells them that he owes them more than he can ever repay. He believes Macbeth has a bright future ahead of him and he promises to help further Macbeth's career. He gives Banquo a reward for his service. He names his son, Malcolm, prince of Cumberland. He praises Macbeth to Banquo, telling him that Macbeth is an unparalleled soldier.
Duncan is very appreciative of those in his service and often demonstrates that gratitude with rewards and promotions. He is a fair leader whose only visible flaw is his trusting nature. This trait results in him being betrayed by both the original Thane of Cawdor and Macbeth and ultimately costs him his life.