Acknowledgment: This work has been summarized using The Complete Works of Shakespeare Updated Fourth Ed., Longman Addison-Wesley, ed. David Bevington, 1997. Quotations are for the most part taken from that work, as are paraphrases of his commentary.
Overall Impression: This is not great Shakespeare in my opinion and lacks impressive language. The plot seems too black and white and lacking in subtlety.
Per Bevington: This plot derives from Plutarch and may be WS's last tragedy. It takes place in the early days of the Roman republic. It deals with the instability and constant upheaval of the republic, the downside of popular rule and democratic extremism, and with Coriolanus's tragic flaws in which his nobility is outweighed by his lack of political realism and tact. The attitude to the competing forms of governance is ambiguous. Coriolanus is honest, lacking tact, out of fashion, unwilling to appease the expectations of the people. He has been taught a code of death before dishonor by his domineering mother--she can never be satisfied even though he present his war achievements to her as love offerings. He is defeated by her overriding ambition for him.
Rome, street. The citizens of Rome are angry with the haughty patrician (and presumably senator) Caius Marcius (the future Coriolanus) and want to kill him because of his arrogance and contempt for the common people. They lack grain and Marcius has refused to open the city's stores to them.
Menenius Agrippa, friend an loyal supporter of Marcius, defends him to the mob and defends the current form of republican government. He tells the allegory of the belly by which the patricians are the entry point through which all nourishment for the body of Rome enters...
Marcius arrives and is openly and tactlessly contemptuous of the rabble, threatens them with his sword, etc. He is also contemptuous of the tribunes Junius Brutus and Sicinius Velutus (tribunes are elected representatives of the plebeians). A messenger arrives to say the Volscians are arming for an attack on Rome. The warlike Marcius welcomes this news to fight again his archenemy Tullus Aufidius. The consul and general Cominus appeals to Marcius to go to war with him against the Volscians and he gladly joins Cominus and the other general in charge, Titus Lartius. Marcius makes more taunts against the tribunes, etc., and they marvel at his insolence.
Corioles, SE of Rome. Aufidius agrees to leave Corioles protected by others and to fight elsewhere. He vows to fight Marcius to the death.
Rome, Marcius' house. His domineering mother Volumnia tells his wife Virgilia about her code of honor, how Virgilia should be proud that her husband is fighting for Rome, etc... Virgilia's friend Valeria visits and they discuss Virgilia's son young Marcius. Valeria tells them Marcius and Lartius are preparing to fight at Corioles.
Before Corioles. Marcius commands a parley at the wall of Corioles. The two sides fight, Marcius pursues the Volscians into the walled town, ends up shut up alone in the city gates initially without any help, and valiantly fights his enemy. Lartius charges in with troops soon.
The Romans have been victorious. Marcius condemns those who are gathering spoils. Lartius praises his deeds.
Near Cominus' camp. Marcius arrives bloodied. He chastises men who are not currently fighting. He refuses to rest and demands to fight Aufidius without assistance.
Before Corioles. More battle...
Marcius confronts Aufidius and they fight, but Aufidius is rescued and taken away.
Cominius praises the heroic and triumphant deeds of Marcius, who shuns such praise. Marcius will accept only the same amount of spoils as the other soldiers. Cominus declares Marcius has won the day and proclaims he will be known thereafter as Caius Marcius "Coriolanus" after the victory at Corioles. Coriolanus asks that a local host who treated him kindly be shown mercy, but cannot remember his name.
Aufidius is angry he has been denied his great fight with Marcius and again proclaims his hatred for him.
Rome. Menenius and the tribunes discuss the war news. The women have learned of Coriolanus' heroism. He now has 27 war wounds. He arrives and is welcomed as a hero. Volumnia praises his accomplishments. She is expecting him to stand for consul, a role which he feels he is unsuited for. The tribunes initially agree to this, but then express reservations about his continued arrogance, refusal to follow the customs associated with such election, etc...
The election for consul takes place. Cominius praises Coriolanus and the senate has agreed he is to be consul. He must now speak to the people and go through the prescribed rituals, but he is resistant.
The citizens come to Coriolanus to ritually question him, see his scars, etc. He tries initially to conform. One citizen, prompted by the tribunes, provokes him and he becomes hostile... The citizens decide he has mocked them and turn on him...
Rome. Coriolanus expresses his contempt for the people. The tribunes inform him he has not passed the peoples vote, and he recognizes the tribunes have plotted against him. He expresses his contempt for them, etc. Sicinius calls him a traitor and calls for aediles (officers of the tribunes) to arrest him. He and Brutus want him executed by being tossed off the Tarpeian rock. Menenius whisks him away and warns there could be a civil war if he is executed.
Coriolanus confers with his noblemen and Volumnia. She counsels him to swallow his pride, play a part, ask forgiveness, speak mildly, etc.
Coriolanus returns to the tribunes. Soon, he cannot restrain his rage toward them, and is again condemned to die, a sentence soon commuted to banishment. He curses them.
Coriolanus says goodbye to V. and V. at the gates of the city. Cominius offers to accompany him but he refuses.
The tribunes resolve to appear more humble now that they have exerted their power against Coriolanus Volumnia curses them, saying they incensed the rabble.
A Roman and a Volscian discuss the strange turn of affairs with Coriolanus...
Coriolanus appears in partial disguise in the city of Antium before Aufidius' house.
He demands to see Aufidius, who eventually receives him warmly as a revered and much admired warrior even though he has been the enemy. Coriolanus agrees to seek his revenge against the Romans...
The tribunes and Marcius' women have heard nothing of him. An Aedile reports the Volscians are massing for an attack, and soon we learn that Marcius has joined with Aufidius... The citizens express regret they have banished him.
Aufidius' men are bothered that Marcius seems to be attracting all the attention away from Aufidius. A. defends him, though to himself he plans to take advantage of him.
Cominius has failed in his embassy to dissuade Coriolanus from the attack. The citizens begin to change their story on how he was banished and who is responsible for it.
Menenius comes to Coriolanus, but is rejected though Coriolanus tells him he loved him.
Coriolanus and Aufidius are planning the attack the next day on Rome. Volumnia and Virgilia appear to him with his son and Valeria, and appeal to him to desist. He rejects them initially, but she urges him not to dishonor his name and to reconcile the Romans and the Volscians. He finally agrees to her request, though he knows he is putting himself in mortal danger by doing so.
Menenius still thinks Coriolanus will attack. A messenger announces the ladies have prevailed. Celebrations.
A senator proclaims the unbanishment of Corialnus.
Aufidius plots with conspirators against Coriolanus. Coriolanus arrives and states he still will serve under Aufidius' command, but offers a document of peace with the Romans. Aufidius accuses him of treason and oath breaking and calls him a "boy of tears" (after his response to his mother's persuasive tears). Coriolanus takes offense and is defiant, Aufidius scorns him, the conspirators attack and kill him. The Volscian lords are taken aback at this treachery but recognize Coriolanus' own impatience played a role. They have the body borne away with respect. Aufidius is overcome with sorrow at the loss of his noble antagonist.