The play begins with a food riot in Rome. A patrician, Menenius, seeks to pacify the discontented citizens. Another, Caius Martius, however, encourages confrontation. The heated atmosphere is temporarily appeased as modest constitutional reform is granted to the plebeians; as a result the citizens are given some form of political representation through five Tribunes.
The tensions within Rome are then focused on the threat of an outside enemy, the Volsces. Volumnia, Caius Martius' mother, supports her son's eagerness for war and the chance of military glory. His wife, however, is apprehensive. Martius is heroic in the war with the Volsces and instrumental to the capture of a neighbouring city, Corioli.
Act I, scene i
'Enter a company of mutinous citizens, with staves, clubs, and other weapons', a street in Rome, en route to the Capitol. We are immersed into an atmosphere of civil disturbance that has been prompted by acute food shortages among the lower orders in Rome. The citizens are resolved 'rather to die than to famish.' Caius Martius is identified as the cause of the trouble, and emerges as a hated figure among the plebeians. The citizens assert a rash and violent solution to their problems: 'Let us kill him, and we'll have corn / at our own price' (ll.9-10). Superficially the disturbance concerns corn prices, but it quickly emerges that the problem is something deeper, rooted in social tension, and the food crisis is merely the catalyst. The First Citizen scathingly observes how the upper echelons of Roman society do nothing to allay the hardship of the poor, but rather ensure the continuance of their impoverished existence to bolster their social and political positions. With the contrast of opinions between the First and Second Citizens about the course of their actions (ll. 13-45), Shakespeare illustrates the difficulties the oppressed have in achieving unity, until a figure of hatred to collectively unleash their tension is found. Shakespeare also demonstrates the fickleness of the plebeians' attitudes - later in the scene the Second Citizen sways in his opinion, and his hostility towards Caius Martius grows firm. Menenius' arrival halts progress of the mob towards the Capitol. The citizens look on Menenius favourably - he is described as 'one that hath / always loved the people' and 'honest enough, would all the rest / were so!' (ll.50-4) Menenius is political and his balanced rhetoric ideal to diffuse the situation.
Menenius likens the state to a ship, with the patrician senators at the helm, guiding affairs. The inflamed citizens are not persuaded by Menenius' first exposition; thus he proceeds to recount the 'belly fable'. The imagery here is important; Menenius recounts a belly fable to starved plebeians, envisages a system of food distribution from the centre that is obviously failing. Menenius' underlying contempt for the citizens and the political necessity of his speech heretofore is exposed when he declares 'Rome and her rats are at the point of battle' (l. 161).
Caius Martius arrives. In contrast to Menenius' attempts to diffuse the situation with reason and friendliness, however duplicitous, Caius Martius is at once aggressive and insults the 'dissentious rogues', disregards the 'poor itch of your opinion', and questions what reason they have to 'Make yourselves scabs?' (ll.162- 4) This language of a disease or ailment illustrates Caius Martius' physical revulsion at the plebeians, affirming his social prejudices. Where Menenius responds to the citizens both collectively and individually, Martius sees only an undifferentiated mass and is enraged by their challenge to and ingratitude for the Senate (ll. 185-7). The reason for Martius' stern words becomes apparent. Menenius points out to Martius that he has diffused the mob, to which Martius responds that the patricians have granted a measure of political constitutional reform with five Tribunes to represent the plebeians in the Senate. Martius expresses his fear for Rome's social hierarchy.
However, Martius is encouraged by the news of war against the Volscians. He envisages war as a means of ridding Rome of some of its 'rabble'. Yet it becomes clear that Martius' enthusiasm for war is more personal than patriotic as he considers the opportunity to engage his Volscian enemy, Aufidius.
Through Martius we see the attitude of the nobles; they expect the citizens to fight for Rome but have no concept of their duty to provide reciprocal obligation in society. At the end of the scene the new Tribunes, who have been ignored up to this point, are left to provide an insightful assessment of what will come from Roman success in war.
Act I, scene ii
Shakespeare moves our attention to a council of the Volscian leaders. We are given insight into the espionage and counter-espionage between the two states, a deceitful activity Martius approves of in war but not during peacetime. This is recalled later when Martius is accused of inconsistency by his mother Volumnia (III.ii.41-5) for this belief. Aufidius resolves to settle his personal animosity with Caius Martius as well as upholding Volscian honour against Rome.
Act I, scene iii
Martius' mother, Volumnia, and his wife, Virgilia, are at their embroidery. The First Citizen has already provided the audience with a hint of the maternal power that governs Martius, and will ultimately seal his tragic end. One of Shakespeare's principal reasons for the inclusion of this scene is an exploration of this influence. While Volumnia is engaged with her embroidery, she speaks easily of slaughter and her pride in Martius' heroism and militarism. Temperamentally, mother and son are very close. The contrast with Virgilia is immediately apparent; while Volumnia speaks of the battlefield, the pacific Virgilia is distressed by any reference to bloodshed. While Virgilia concerns herself with Martius' safety, Volumnia is occupied of hopes he will bring glory to himself, his family and Rome. Shakespeare favoured investigating delusions about honour, and for Volumnia honour obscures the suffering of war and social prejudice. She imagines her son valiantly defeating his foe Aufidius, or leading the citizens in the Roman army - 'Come on you cowards, you were got in fear / Though you were born in Rome.' (ll.30-4)
In Volumnia's speech the imagery of war is closely intertwined with sexuality (ll.2-5, 40-3). Further unification of imagery occurs with the fusion of the idea of Martius as warrior and harvester (ll.34-7). Death was frequently depicted as a harvester. As the scene progresses we become more aware that Volumnia is a representation of the classic idea of Roman virtue. Virgilia, with her humanity, reveals a moral virtue that is more of Shakespeare's own time than valour and military endeavour. In consequence, in contrast to Volumnia, Virgilia exerts a very different force over her husband and her humanity and small part in the play emphasises the absence of that virtue in Rome.
Act I, scene iv
The senators address the Romans from the walls of the Corioli. Meanwhile the Volscian army leaves the city gates and attacks the Romans. As the Roman soldiers are forced to retreat, Martius scorns them for their cowardice and recalls the diseased imagery of inferior classes (ll. 30-33). Martius decides the army must turn and re- engage the Volsci. When pursuit of the Volsci, Martius finds himself alone. Believed dead by his comrades, he valiantly fights off his foes. Under Lartius's leadership, the Romans storm the city gates and seize the town.
Act I, scene v
Inside the Roman army plunder and lay waste to Corioli. Martius is contemptuous of the soldiers' behaviour. Playing down the extent of his wounds, Martius gives his attentions to Cominius, who confronts the main army of the Volsci. This may be more through determination to engage Aufidius and settle personal animosity than loyalty to Cominius.
Act I, scene vib>
Martius plays down the extent of his wounds. Cominius welcomes Martius, who is keen to pursue the battle, and abruptly interrupts the former's enquiry into his deeds at Corioli:
'Where is the enemy? Are you lords o'th' field?
If not, why cease you till you are so?'
(ll. 47-8)
Martius asks Cominius to put him into the field opposite Aufidius. That he is intent on mixing the glory of Rome with personal vendetta is apparent. In asking for volunteers, Martius requests only men who 'think brave death outweighs bad life, / And that his country's dearer than himself.' (ll.71-2)
Act I, scene vii
Shakespeare switches location to Lartius inside Corioles and eager to join Cominius and Martius in the battle against Aufidius.
Act I, scene viii
This scene focuses on a duel between the arch-rivals Aufidius and Martius. Aufidius receives support from his army, which enrages the Volscian commander: 'Officious, and not valiant, you have sham'd me / In your condemn'd seconds' (ll.14-15).
Act I, scene ix
Victory is now with Rome. Cominius acknowledges Martius' great heroic contribution to the battle and anticipates his reception in Rome. Even the citizens, Cominius predicts, will 'thank the gods / Our Rome hath such a soldier'. Martius refuses Cominius' offer of one tenth of the plunder. Martius is uneasy with praise or commendation - hence his reaction to that of Cominius, Volumnia or even the martial trumpets. Here we see Martius' character - he is a soldier. Later the shift from Roman to Volscian army is easier than that from the army to the world of politics for Martius. He has one request that a man who sheltered him in Corioli be released from prison. Yet consumed by the personal rivalry with Aufidius, Martius cannot remember the man's name; this symbolises the hero's tragedy - that his personal integrity is subservient to his integrity as a soldier.
Act I, scene x
Aufidius stands defeated for the fifth time by Coriolanus, though he refuses to see himself as a part of the Volscian defeat against Rome. He is more concerned by the former than the latter, which establishes the importance of personal rivalry in the conspiracy against Coriolanus that will materialise in Act V. Aufidius will resort to any means to achieve this, military or political, and in this, the contrast with Coriolanus is acute. Further Coriolanus' exile in Act IV parallels Aufidius' voluntary exile here. That this retreat will be temporary is confirmed as Aufidius asks for reports to be brought to him.