Shakespeare's Scottish play has given some of the characters of eleventh-century Scotland a celebrity which they would not otherwise have been accorded. Like many other dramatic reconstructions of the past, however, Shakespeare's portrayal of MacBeth leaves much to be desired when viewed from the standpoint of sober history. Shakespeare, of course, relied on the sources of information available to him, and they were unsympathetic towards a ruler who, although of royal lineage, had usurped the throne when Duncan I was killed at Pitgaveny near Elgin in 1040, but yet had not succeeded in establishing a ruling dynasty. Because subsequent Scottish kings were all descended from Duncan, it is not surprising that MacBeth's reign came to be seen as an unfortunate interlude, a regrettable reversion towards barbarism in what was otherwise an age of progress.

In fact MacBeth was a successful ruler. By contemporary standards the length of his reign was highly respectable, and Scotland was sufficiently peaceful for him to be confident enough to leave it in 1050 to make a pilgrimage to Rome. A Latin poem describes his reign as a fertile period, which suggests favourable weather but also points to an absence of the civil strife which always brings hardship in a rural society. There is no hint in contemporary sources that he was a tyrant, and it is inconceivable that he would have reigned for so long if he had been.