Duncan, in consternation at this news, assembled his council, at which Macbeth, after having blamed the king severely for his lenity and slackness in punishing the offenders, which had given them time to collect an army, offered to undertake the conduct of the war in concert with Banquo. His offer was gladly accepted, and the mere report of his approach with fresh troops struck such terror into the rebels, that a great number of them secretly deserted; and Macdowald, having tried to make head against Macbeth with the remainder, was utterly routed, and forced to fly to a castle in which he had placed his wife and children; but, despairing of being able to hold out, and fearing the cruelties of his opponents, he killed himself, after having first put his wife and children to death. Macbeth entered without obstacle into the castle, the gates of which had been left open. He found only the body of Macdowald in the midst of his murdered family; and the barbarism of that rude age was revolted by the fact that, unmoved by this tragic spectacle, Macbeth cut off Macdowald's head, and sent it to the king, and hanged the body upon a gallows. He made the inhabitants of the isles purchase the pardon of their revolt at a very high price, which did not, however, prevent him from putting to execution all those whom he could find in Lochaber. The inhabitants exclaimed loudly against this violation of his pledge, and the reproaches which they heaped upon him irritated Macbeth to such a degree that he was on the point of crossing over to the isles with an army to take vengeance upon them; but he was dissuaded from this project by the counsels of his friends, and more particularly by the presents with which the islanders a second time purchased their pardon.

A short time afterward, Sweno, king of Norway, having made a descent upon Scotland, Duncan, to resist him, placed himself at the head of the largest portion of his army, and intrusted the rest to the command of Macbeth and Banqno. Duncan was defeated and put to flight; and he took refuge in the castle of Perth, in which he was besieged by Sweno. Duncan, having secretly informed Macbeth of his intentions, feigned a desire to surrender, and protracted the negotiation, until at last, having learned that Macbeth had collected a sufficient force, he appointed a day for giving up the fortress; and, meanwhile, he offered to send the Norwegians a supply of provisions, which they accepted all the more eagerly because they had suffered greatly from famine for several days. The bread and ale with which he furnished them had been adulterated with the juice of an extremely narcotic berry, so that, having eaten and drank greedily, they fell into "a fast dead sleep, that in manner it was impossible to awake them." Then Duncan sent word to Macbeth, who arriving in all haste, and entering without opposition into the camp, massacred almost all the Norwegians, most of whom never stirred, while the others were rendered so dizzy by the effects of the narcotic that they could make no defense. A large number of sailors from the Norwegian fleet, who had come to share in the abundance which prevailed in the camp, shared also in the fate of their fellow-countrymen; and Sweno, who escaped with ten others from this butchery, could scarcely find enough mariners to man the ship in which he fled to Norway. Those vessels which he left behind were, three days afterward, so tossed by an east wind, "that, beating and rushing one against another, they sank there," at a place called Drownelow Sands, where they lie "even unto these days (1574), to the great danger of other such ships as come on that coast; for, being covered with the flood when the tide cometh, at the ebbing again of the same some parts of them appear above water."

This disaster caused such consternation in Norway, that, for many years afterward, no knights were made until they had sworn to avenge their countrymen who had thus been slaughtered in Scotland. Duncan, in celebration of his deliverance, ordered solemn processions to be made throughout the realm; but while these thanksgivings were in progress, he was informed of the disembarkation of an army of Danes, under the command of Canute, king of England, who had come to avenge the defeat of his brother Sweno. Macbeth and Banquo hastened to meet them, defeated them in a pitched battle, and forced them to re-embark, and to pay a considerable sum for permission to bury their dead at St. Colm's Inch, where, says the chronicle, "many old sepulchres are yet to be seen graven with the arms of the Danes."

Such are the exploits of Macbeth and Banquo, of which Shakspeare, following Holinshed, has made use in his tragedy. A short time afterward, Macbeth and Banquo were traveling to Forres, where the king then lay, "and went sporting by the way together, without other company save only themselves," when they were suddenly accosted by three women "in strange and wild apparel, resembling creatures of the elder world," who saluted Macbeth precisely as it is related in the tragedy. Upon this, Banquo said, "What manner of women are you that seem so little favorable unto me, whereas, to my fellow here, besides high offices, ye assign also the kingdom, appointing forth nothing for me at all?" "Yes," saith the first of them, "we promise greater benefits unto thee than unto him, for he shall reign, indeed, but with an unlucky end; neither shall he leave any issue behind him to succeed in his place; whereas, contrarily, thou indeed shalt not reign at all, but of thee those shall be born who shall govern the Scottish kingdoms by long order of continual descent." Herewith the women immediately disappeared. Soon afterward, the thane of Cawdor having been put to death for treason, his title was conferred upon Macbeth, who now began, as well as Banquo, to place great faith in the predictions of the witches, and to devise means for obtaining the crown.

He had a good chance of succeeding legitimately to the throne, for Duncan's sons were not yet of age to reign, and the law of Scotland ordained that, if the king died before his sons or direct descendants were old enough to undertake the management of affairs, the nearest relative of the deceased king should be elected in their stead. But Duncan having appointed his son Malcolm, while still under age, Prince of Cumberland and successor to the throne, Macbeth, who saw his hopes destroyed by this proceeding, thought himself entitled to take revenge for the injustice he had experienced. To this, moreover, he was incessantly stimulated by his wife, Guach, who, burning with desire to bear the name of queen, and being, says Boetius, "like all women, impatient of delay," continually reproached him with his want of courage. Macbeth, therefore, having assembled a large number of his friends at Inverness, or, as some say, at Botgosuane, communicated to them his design, killed Duncan, and repaired with his party to Scone, where he obtained possession of the crown without difficulty.

Holinshed's chronicle relates the murder of Duncan without any detail. The incidents which Shakspeare has interwoven into his drama are taken from another part of the same chronicle concerning the murder of King Duff, who had been assassinated more than sixty years before by a Scottish lord named Donwald. The following are the circumstances of this murder, as related in the chronicle:

Duff had shown himself, from the commencement of his reign, very anxious to protect the people against malefactors, and "idle persons who sought to live only upon other men's goods." He put several to death, and compelled others to withdraw to Ireland, or else to learn "some manual occupation wherewith to get their living." Although, as it would appear, these fellows were connected only in a very remote degree with the high nobility of Scotland, the nobles, says the chronicle, "were much offended with this extreme rigor, accounting it a great dishonor for such as were descended of noble parentage to be constrained to get their living with the labor of their hands, which only appertained to plowmen, and such others of the base degree as were born to travail for the maintenance of the nobility, and to serve at their commandment." The king was consequently regarded by them as an enemy of the nobles, and unworthy to govern them, as he was, they said, devoted solely to the interests of the people and clergy, who at that time made common cause against the oppression of the great lords. The discontent increased daily, and several rebellions arose, in one of which some young gentlemen engaged, who were relatives of Donwald, the king's lieutenant of the castle of Forres. These young men were taken prisoners, and Donwald, who until then had faithfully and usefully served the king, hoped to obtain their pardon; but not succeeding in his attempt, he was filled with resentment. His wife, who was irritated against the king from a similar cause, spared no efforts to increase his anger, and reminded him how easy it would be to take his revenge when Duff came, as frequently happened, to reside at Forres without any other guard than the garrison of the castle, which was entirely devoted to them; and "she showed him the means whereby he might soonest accomplish it."