From the Agrarian Law of Sp. Cassius to the appointment of the Decemvirs was a period of more than thirty years. During the whole of this time the struggle between the Patricians and the Plebeians was increasing. The latter constantly demanded, and the former as firmly refused, the execution of the Agrarian Law of Cassius. But, though the Plebeians failed in obtaining this object, they nevertheless made steady progress in gaining for themselves a more important position in the city. In B.C. 471 the Publilian Law was carried, by which the election of the Tribunes and Plebeian Ædiles was transferred from the Comitia of the Centuries to those of the Tribes.[17] From this time the Comitia of the Tribes may be regarded as one of the political assemblies of the state, ranking with those of the Centuries and the Curies. But the Patricians still retained exclusive possession of the administrative and judicial powers, and there were no written laws to limit their authority and to regulate their decisions. Under these circumstances, the Tribune C. Terentilius Arsa proposed, in B.C. 462, that a commission of Ten Men (Decemviri) should be appointed to draw up a code of laws, by which a check might be put to the arbitrary power of the Patrician magistrates. This proposition, as might have been expected, met with the most vehement opposition from the Patricians. But the Plebeians were firm, and for five successive years the same Tribunes were re-elected. It was during this struggle that an attempt was made upon the Capitol by Herdonius, a Sabine chief, with a band of outlaws and slaves. It was a turbulent period, and the Patricians had recourse even to assassination. At length, after a struggle of eight years, a compromise was effected, and it was arranged that Three Commissioners (Triumviri) were to be sent into Greece to collect information respecting the laws of Solon at Athens, as well as of the other Greek states. After an absence of two years the three commissioners returned to Rome (B.C. 452), and it was now resolved that a Council of Ten, or Decemvirs, should be appointed to draw up a code of laws, and, at the same time, to carry on the government and administer justice. All the other magistrates were obliged to abdicate, and no exception was made even in favor of the Tribunes. The Decemvirs were thus intrusted with supreme power in the state. They entered upon their office at the beginning of B.C. 451. They were all Patricians. At their head stood Appius Claudius and T. Genucius, who had been already appointed consuls for the year. They discharged the duties of their office with diligence, and dispensed justice with impartiality. Each administered the government day by day in succession, and the fasces were carried only before the one who presided for the day. They drew up a Code of Ten Tables, in which equal justice was dealt out to both orders. The Ten Tables received the sanction of the Comitia of the Centuries, and thus became law.

On the expiration of their year of office all parties were so well satisfied with the manner in which the Decemvirs had discharged their duties that it was resolved to continue the same form of government for another year, more especially as some of them said that their work was not finished. A new Council of Ten was accordingly elected, of whom Appius Claudius alone belonged to the former body. He had so carefully concealed his pride and ambition during the previous year that he had been the most popular member of the council, and the Patricians, to prevent his appointment for another year, had ordered him to preside at the Comitia for the elections, thinking that he would not receive votes for himself. But Appius set such scruples at defiance, and not only returned himself as elected, but took care that his nine colleagues should be subservient to his views. He now threw off the mask he had hitherto worn, and acted as the tyrant of Rome. Each Decemvir was attended by twelve lictors, who earned the fasces with the axes in them, so that 120 lictors were seen in the city instead of 12. The Senate was rarely summoned. No one was now safe, and many of the leading men quitted Rome. Two new Tables were added to the Code, making twelve in all; but these new laws were of the most oppressive kind, and confirmed the Patricians in their most odious privileges.

When the year came to a close the Decemvirs neither resigned nor held Comitia for the election of successors, but continued to hold their power in defiance of the Senate and of the People. Next year (B.C. 449) the Sabines and Æquians invaded the Roman territory, and two armies were dispatched against them, commanded by some of the Decemvirs. Appius remained at Rome to administer justice. But the soldiers fought with no spirit under the command of men whom they detested, and two acts of outrageous tyranny caused them to turn their arms against their hated masters. In the army fighting against the Sabines was a centurion named L. Sicinius Dentatus, the bravest of the brave. He had fought in 120 battles; he had slain eight of the enemy in single combat; had received 40 wounds, all in front; he had accompanied the triumphs of nine generals; and had war-crowns and other rewards innumerable. As Tribune of the Plebs four years before, he had taken an active part in opposing the Patricians, and was now suspected of plotting against the Decemvirs. His death was accordingly resolved on, and he was sent with a company of soldiers as if to reconnoitre the enemy's position. But in a lonely spot they fell upon him and slew him, though not until he had destroyed most of the traitors. His comrades, who were told that he had fallen in an ambush of the enemy, discovered the foul treachery that had been practiced when they saw him surrounded by Roman soldiers who had evidently been slain by him. The Decemvirs prevented an immediate outbreak only by burying Dentatus with great pomp, but the troops were ready to rise in open mutiny upon the first provocation.

In the other army sent against the Æquians there was a well-known centurion named Virginius. He had a beautiful daughter, betrothed to L. Icilius, an eminent leader of the Plebeian order. The maiden had attracted the notice of the Decemvir Appius Claudius. He at first tried bribes and allurements, but when these failed he had recourse to an outrageous act of tyranny. One morning, as Virginia, attended by her nurse, was on the way to her school, which was in one of the booths surrounding the forum, M. Claudius, a client of Appius, laid hold of the damsel and claimed her as his slave. The cry of the nurse for help brought a crowd around them, and all parties went before the Decemvir. In his presence Marcus repeated the tale he had learnt, asserting that Virginia was the child of one of his female slaves, and had been imposed upon Virginius by his wife, who was childless. He farther stated that he would prove this to Virginius as soon as he returned to Rome, and he demanded that the girl should meantime be handed over to his custody. Appius, fearing a riot, said that he would let the cause stand over till the next day, but that then, whether her father appeared or not, he should know how to maintain the laws. Straightway two friends of the family made all haste to the camp, which they reached the same evening. Virginius immediately obtained leave of absence, and was already on his way to Rome, when the messenger of Appius arrived, instructing his colleagues to detain him. Early next morning Virginius and his daughter came into the forum with their garments rent. The father appealed to the people for aid, and the women in their company sobbed aloud. But, intent upon the gratification of his passions, Appius cared not for the misery of the father and the girl, and hastened to give sentence, by which he consigned the maiden to his client. Appius, who had brought with him a large body of patricians and their clients, ordered his lictors to disperse the mob. The people drew back, leaving Virginius and his daughter alone before the judgment-seat. All help was gone. The unhappy father then prayed the Decemvir to be allowed to speak one word to the nurse in his daughter's hearing, in order to ascertain whether she was really his daughter. The request was granted. Virginius drew them both aside, and, snatching up a butcher's-knife from one of the stalls, plunged it into his daughter's breast, exclaiming, "There is no way but this to keep thee free." In vain did Appius call out to stop him. The crowd made way for him, and, holding his bloody knife on high, he rushed to the gate of the city and hastened to the army. His comrades espoused his cause, expelled their commanders, and marched toward Rome. They were soon joined by the other army, to whom Numitorius and Icilius had carried the tidings. The Plebeians in the city flocked to them, and they all resolved to retire once more to the Sacred Mount.

This second secession extorted from the Patricians the second great charter of the Plebeian rights. The Patricians compelled the Decemvirs to resign, and sent L. Valerius and M. Horatius, two of the most eminent men of their order, to negotiate with the Plebeians. It was finally agreed that the Tribunes should be restored, that the authority of the Comitia Tributa should be recognized, and that the right of appeal to the people against the power of the supreme magistrates should be confirmed. The Plebeians now returned to the city, and elected, for the first time, ten Tribunes instead of five, a number which remained unchanged down to the latest times. Virginius, Icilius, and Numitorius were among the new Tribunes.

Two Consuls were elected in place of the Decemvirs, and the choice of the Comitia Centuriata naturally fell upon Valerius and Horatius. The new Consuls now redeemed their promises to the Plebeians by bringing forward the laws which are called after them, the Valerian and Horatian Laws. These celebrated laws enacted:

1. That every Roman citizen should have the right of appeal against the sentence of the supreme magistrate. This was, in fact, a solemn confirmation of the old law of Valerius Publicola, passed in the first year of the republic. It was enacted again a third time in B.C. 300, on the proposal of M. Valerius, the Consul. These repeated enactments gave a still farther sanction to the law. In the same way the Great Charter of England was ratified several times.

2. That the Plebiscita, or resolutions passed by the Plebeians in the Comitia Tributa, should have the force of laws, and should be binding alike upon Patricians and Plebeians.

3. That the persons of the Tribunes, Ædiles, and other Plebeian magistrates should be sacred, and whoever injured them should be sold as a slave.

Virginius now accused Appius Claudius, who was thrown into prison to await his trial. But the proud Patrician, seeing that his condemnation was certain, put an end to his own life. Oppius, another of the Decemvirs, and the personal friend of Appius, was condemned and executed. The other Decemvirs were allowed to go into exile, but they were all declared guilty, and their property confiscated to the state.

The Twelve Tables were always regarded as the foundation of the Roman law, and long continued to be held in the highest estimation. But they probably did little more than fix in a written form a large body of customary law, though even this was a benefit to the Plebeians, as they were no longer subject to the arbitrary decisions of the Patrician magistrates. The Patricians still retained their exclusive privileges; and the eleventh table even gave the sanction of law to the old custom which prohibited all intermarriage (connuubium) between the two orders.