A further attempt was made to get rid of the tribunician power by securing to the plebeians equality of rights in a more regular and more effectual way. The tribune of the people, Gaius Terentilius Arsa, proposed in 292 the nomination of a commission of five men to prepare a general code of law by which the consuls should in future be bound in exercising their judicial powers. But the senate refused to sanction this proposal, and ten years elapsed ere it was carried into effect - years of vehement strife between the orders, and variously agitated moreover by wars and internal troubles. With equal obstinacy the party of the nobles hindered the concession of the law in the senate, and the plebs nominated again and again the same men as tribunes. Attempts were made to obviate the attack by other concessions. In the year 297 an increase of the tribunes from four to ten was sanctioned - a very dubious gain; and in the following year, by an Icilian plebiscitum which was admitted among the sworn privileges of the plebs, the Aventine, which had hitherto been a temple-grove and uninhabited, was distributed among the poorer burgesses as sites for buildings in heritable occupancy. The plebs took what was offered to them, but never ceased to insist in their demand for a legal code. At length, in the year 300, a compromise was effected; the senate in substance gave way. The preparation of a legal code was resolved upon; for that purpose, as an extraordinary measure, the centuries were to choose ten men who were at the same time to act as supreme magistrates in room of the consuls (decemviri consulari imperio legibus scribundls), and to this office not merely patricians, but plebeians also might be elected. These were here for the first time designated as eligible, though only for an extraordinary office. This was a great step in the progress towards full political equality; and it was not too dearly purchased, when the tribunate of the people as well as the right of appeal were suspended while the decemvirate lasted, and the decemvirs were simply bound not to infringe the sworn liberties of the community. Previously however an embassy was sent to Greece to bring home the laws of Solon and other Greek laws; and it was only on its return that the decemvirs were chosen for the year 303. Although they were at liberty to elect plebeians, the choice fell on patricians alone - so powerful was the nobility still - and it was only when a second election became necessary for 304, that some plebeians were chosen - the first non-patrician magistrates that the Roman community had.
Taking a connected view of these measures, we can scarcely attribute to them any other design than that of substituting for tribunician intercession a limitation of the consular powers by written law. On both sides there must have been a conviction that things could not remain as they were, and the perpetuation of anarchy, while it ruined the commonwealth, was in reality of no benefit to any one. People in earnest could not but discern that the interference of the tribunes in administration and their action as prosecutors had an absolutely pernicious effect; and the only real gain which the tribunate brought to the plebeians was the protection which it afforded against a partial administration of justice, by operating as a sort of court of cassation to check the caprice of the magistrate. Beyond doubt, when the plebeians desired a written code, the patricians replied that in that event the legal protection of tribunes would be superfluous; and upon this there appears to have been concession by both sides. Perhaps there was never anything definitely expressed as to what was to be done after the drawing up of the code; but that the plebs definitely renounced the tribunate is not to be doubted, since it was brought by the decemvirate into such a position that it could not get back the tribunate otherwise than by illegal means. The promise given to the plebs that its sworn liberties should not be touched, may be referred to the rights of the plebeians independent of the tribunate, such as the provocatio and the possession of the Aventine. The intention seems to have been that the decemvirs should, on their retiring, propose to the people to re-elect the consuls who should now judge no longer according to their arbitrary pleasure but according to written law.
The plan, if it should stand, was a wise one; all depended on whether men's minds exasperated on either side with passion would accept that peaceful adjustment. The decemvirs of the year 303 submitted their law to the people, and it was confirmed by them, engraven on ten tables of copper, and affixed in the Forum to the rostra in front of the senate-house. But as a supplement appeared necessary, decemvirs were again nominated in the year 304, who added two more tables. Thus originated the first and only Roman code, the law of the Twelve Tables. It proceeded from a compromise between parties, and for that very reason could not well have contained any changes in the existing law of a comprehensive nature, going beyond the regulation of secondary matters and of the mere adaptation of means and ends. Even in the system of credit no further alleviation was introduced than the establishment of a - probably low - maximum of interest (10 per cent) and the threatening of heavy penalties against the usurer-penalties, characteristically enough, far heavier than those of the thief; the harsh procedure in actions of debt remained at least in its leading features unaltered. Still less, as may easily be conceived, were changes contemplated in the rights of the orders. On the contrary the legal distinction between burgesses liable to be taxed and those who were without estate, and the invalidity of marriage between patricians and plebeians, were confirmed anew in the law of the city. In like manner, with a view to restrict the caprice of the magistrate and to protect the burgess, it was expressly enacted that the later law should uniformly have precedence over the earlier, and that no decree of the people should be issued against a single burgess. The most remarkable feature was the exclusion of appeal to the comitia tributa in capital causes, while the privilege of appeal to the centuries was guaranteed; which admits of explanation from the circumstance that the penal jurisdiction was in fact usurped by the plebs and its presidents[11], and with the tribunate there necessarily fell the tribunician capital process, while it was perhaps the intention to retain the aedilician process of fine (multa). The essential political significance of the measure resided far less in the contents of the legislation than in the formal obligation now laid upon the consuls to administer justice according to these forms of process and these rules of law, and in the public exhibition of the code, by which the administration of justice was subjected to the control of publicity and the consul was compelled to dispense equal and truly common justice to all.
The end of the decemvirate is involved in much obscurity. It only remained - so runs the story - for the decemvirs to publish the last two tables, and then to give place to the ordinary magistracy. But they delayed to do so: under the pretext that the laws were not yet ready, they themselves prolonged their magistracy after the expiry of their official year--which was so far possible, as under Roman constitutional law the magistracy called in an extraordinary way to the revision of the constitution could not become legally bound by the term set for its ending. The moderate section of the aristocracy, with the Valerii and Horatii at their head, are said to have attempted in the senate to compel the abdication of the decemvirate; but the head of the decemvirs Appius Claudius, originally a rigid aristocrat, but now changing into a demagogue and a tyrant, gained the ascendancy in the senate, and the people submitted. The levy of two armies was accomplished without opposition, and war was begun against the Volscians as well as against the Sabines. Thereupon the former tribune of the people, Lucius Siccius Dentatus, the bravest man in Rome, who had fought in a hundred and twenty battles and had forty-five honourable scars to show, was found dead in front of the camp, foully murdered, as it was said, at the instigation of the decemvirs. A revolution was fermenting in men's minds; and its outbreak was hastened by the unjust sentence pronounced by Appius in the process as to the freedom of the daughter of the centurion Lucius Verginius, the bride of the former tribune of the people Lucius Icilius - a sentence which wrested the maiden from her relatives with a view to make her non-free and beyond the pale of the law, and induced her father himself to plunge his knife into the heart of his daughter in the open Forum, to rescue her from certain shame. While the people in amazement at the unprecedented deed surrounded the dead body of the fair maiden, the decemvir commanded his lictors to bring the father and then the bridegroom before his tribunal, in order to render to him, from whose decision there lay no appeal, immediate account for their rebellion against his authority. The cup was now full. Protected by the furious multitude, the father and the bridegroom of the maiden made their escape from the lictors of the despot, and while the senate trembled and wavered in Rome, the pair presented themselves, with numerous witnesses of the fearful deed, in the two camps. The unparalleled tale was told; the eyes of all were opened to the gap which the absence of tribunician protection had made in the security of law; and what the fathers had done their sons repeated. Once more the armies abandoned their leaders: they marched in warlike order through the city, and proceeded once more to the Sacred Mount, where they again nominated their own tribunes. Still the decemvirs refused to lay down their power; then the army with its tribunes appeared in the city, and encamped on the Aventine. Now at length, when civil war was imminent and the conflict in the streets might hourly begin, the decemvirs renounced their usurped and dishonoured power; and the consuls Lucius Valerius and Marcus Horatius negotiated a second compromise, by which the tribunate of the plebs was again established. The impeachment of the decemvirs terminated in the two most guilty, Appius Claudius and Spurius Oppius, committing suicide in prison, while the other eight went into exile and the state confiscated their property. The prudent and moderate tribune of the plebs, Marcus Duilius, prevented further judicial prosecutions by a seasonable use of his veto.