Duncan gives him the title. Ross delivers the news to Macbeth.
Ross uses the titles "loyal Thane of Cawdor" and "Greater Thane of Cawdor" to refer to Macbeth when he informs him of his new title.
The king has decided to give Macbeth the title of Thane of Cawdor as a reward for his bravery and loyalty in battle.
Ross informs Macduff that Macduff's family has been murdered on the orders of Macbeth.
Some people might think that Duncan gives this title to Macbeth because Macbeth was instrumental in capturing the traitor Thane of Cawdor. But this is wrong. The Thane of Ross brings the news to Duncan of Cawdor's treachery but does not name Macbeth as the man that captures him. Ross is then told to find Macbeth and tell him that he is now the Thane of Cawdor. When Ross tells him this, Macbeth is astonished: he says "The thane of Cawdor lives--a prosperous gentleman! Why do you dress me in borrowed robes?" He would not have been astonished had he been the man to capture Cawdor. What is more, Ross is not surprised that he is astonished, because Ross knows that Macbeth has not yet heard of Cawdor's treachery. It is possible that Duncan misunderstood Ross's report and believed that Macbeth could simultaneously be in Forres (in northern Scotland) and Fife (in southern Scotland) fighting two different battles at the same time. If he was that much of a dimwit about the geography of the country he was supposed to be king of, then he might have rewarded Macbeth for something he did not do. It is far more likely that Macbeth receives the title either because Duncan wants to reward the brave and victorious Macbeth who defeated Macdonweald, or that his choice of Macbeth as the recipient is entirely arbitrary.
Ross, he told them in England. Just before they go to war against Scotland and Macbeth
Macbeth has been appointed Thane of Cawdor.
Lady Macbeth is the wife of the title character, Macbeth, a Scottish nobleman.
Ross. Ross always seems to be a messenger. When we first meet him he has travelled all the way north to Forres from Fife to report about a battle which has been going on down there. Later we see him bringing a warning to Lady Macduff and then as a messenger bringing the news of Lady Macduff's death to Macduff.
King Duncan orders Ross to go inform Macbeth of his promotion to Thane of Cawdor and to thank the former Thane of Cawdor for his traitorous actions.
Macdonweald. He split him from the nave to the chops. Macbeth did not capture the Thane of Cawdor because when Ross greets him with the title, Macbeth says "The Thane of Cawdor lives, a prosperous gentleman. Why do you dress me in borrowed robes?" Had Macbeth captured him, he would not have thought that he was a "prosperous gentleman" and Ross would not have to explain to him that the former Thane was a traitor.
Perhaps the title "King of Scotland" which they both held may give you a clue.