This is a story about a General who is thrust into the world of politics, namely because he was such a good general. However, while he happpens to be a great general, as a politician he positively sucks. Basically, Gaius Marcius' main flaw (despite the fact that I don't believe in fatal flaws) is that he simply speaks his mind, which is a noble characteristic is most professions, but not in politics. To put it bluntly, Marcius (aka Coriolanus, a name he receives after capturing the city of Coriolai) has absolutely no time for the hoi poloi (namely the great unwashed, the peasantry, the plebeians, or whatever other name you can come up with that describes those of us who are not members of the ruling class) and he does not mince any words regarding this dislike. This is clear right from the beginning for when the people are rioting over the price of grain he basically tells them to bugger off, and no amount of whinging and whining was going to make him release any more grain, because, well, there is not all that much grain to go around, and if they didn't put up and shut up, then he was going to start busting some heads – and this is from the guy that later in the play is being positioned to become consul of Rome, a position equivalent to president.
The thing I like about Coriolanus is that it gives us an idea into the way politics worked in Republican Rome. Okay, it is Shakespeare, and if we want a better understanding we need to go to the ancient sources, however Coriolanus still gives us a pretty good idea of what the system was like. Basically, in Republican Rome, (as in other ancient democracies) the military and the government were intertwined, so it was not uncommon for the members of the senate and the rulers to have been soldiers and generals. This was the case with Julius Ceaser. However, to be a great ruler one generally had to be a great general, be loved by the patricians, and also be loved by the plebeians (or at least tolerated). Now for Coriolanus: he met two of the three conditions, namely he was not loved by the people (and there was a similar situation with Ceaser, but it was the opposite in that he was loved by the people but hated by the patricians).
These days the idea of a general being a president in an advanced democracy generally does not happen, (though it has happened in the United States with George Washington, Ulysses S Grant, and Eisenhower as examples, but generally the military to not go into politics). However, Rome was quite different, namely because the military was so intertwined with civilian life. Civilians would have participated in the military - especially in times of war. In fact many of the middle class citizens had gained their status after stints in the Roman army (it was common for soldiers who had served in the army to be given plots of land to farm after retiring from the army). As such, one of the rewards for being an outstanding soldier (such as Coriolanus) was a nice plump position in government, and the better the soldier you were, the higher up the chain you could get.
However, Coriolanus' problem was that to become Consul, he needed the consent of the people, and while his political allies could sway the people, his political enemies could also sway them the other way, which is what happened. Basically, the tribunes, who represented the people, and could veto rulings on behalf of the people, swayed them away from Coriolanus, and to such an extent that he was forced to go into exile. In doing so, however, he ends up defecting over to his enemy forces, and fuming in anger over being kicked out of his homeland, he leads his new found allies (the Volsces) against Rome and besieges the city.
The problem was that Coriolanus' as at heart a Roman, and while he was angry at his treatment, he could not stay angry at his people for too long, which turns out bad for him because when he signs the peace treaty with Rome on behalf of the Volsces, and withdawls his forces, he ends up angering the Volsces, who then proceed to kill him.
There was a movie recently released based on this play, starring Ralph Finness. This is actually set in a modern setting, and it is a pretty good movie. For a play that is not performed all that much, if you want to actually see a version of this play, I would highly recommend getting your hands on that movie.
If you are interesting in some more thoughts on the play, I have written a blog post, which I did after watching the Donmar Theatre production.