The movie The Last King of Scotland, released in 2006, is aptly named re-telling of the themes of Macbeth.
The film chronicles the dictatorship of Idi Amin, who savagely ruled Uganda from 1971-1979. During that time, the country was victim to genocide and crimes against humanity that rivaled Macbeth's. Some say Amin killed as many as 300,000. Amin committed the following human rights abuses: ethnic persecutions, extrajudicial killings, nepotism, corruption, forces exile and expulsions.
So says one critic:
If MacBeth is the play whose name you should never utter, then the story of Idi Amin’s ghastly dictatorship in Uganda seems like a modern version of that old Scottish play. Giles Foden’s excoriating novel told of a smartass young doctor, just graduated from his Scottish University, primed and ready for adventure, and Foden pitches his hero into a very palpable hell indeed.
The previous thoughts were quite accurate. I think that I would tend to go in a different way, in terms of addressing the subtleties within a crisis of conscience. One of the most compelling aspects of the character is that there is a legitimate crisis of whether or not what is in his mind is something that should be undertaken. Of course, by the end of the drama, there is little to indicate that there ever was a sense of ambiguity in both thought and action. I liken the initial sense of doing something that one knows is wrong to Richard Nixon and his treatment of "the enemies list" as well as the actions against his political opponents in the early 1970s. I think that there is a sense of moral depravity in his actions, but also tempered with a sense of questioning about whether or not such actions should be undertaken. This complexity is something I see in both characters. On a much smaller level, Tanya Harding could represent a Macbeth- like character in her willingness to do whatever was needed to eliminate her competition. Certainly, the two are not even comparable in scope, but the character makeup might have some level of similarity. Along these lines, one could take any figure from the "steroid era" in baseball, such as Sammy Sosa, Barry Bonds, or Roger Clemens. These are individuals whose ambition to be the very best helped to cloud their judgment and ones who engaged in a professional and moral depravity, only to see their professional worlds and post- playing status completely decline afterwards.
To me, the major character traits of Macbeth are his ambition (desire for power) and his utter ruthlessness in his pursuit of that power. I think that you can find all sorts of historical figures who had similar character traits.
Although Macbeth does not commit any mass murders (he kills plenty of people or has them killed, but not in huge numbers), I would compare him to some of the really brutal dictators of the 20th century -- perhaps Hitler and Stalin.
Both Hitler and Stalin were men who wanted more power for themselves and their countries. Both of them were willing to kill people who had been their comrades (like Banquo) to do this. They were also willing to kill innocent people (like Macduff's family). So these are the two figures I would pick, even though Macbeth did not kill anywhere near as many people as they did.