Titus Livius (Livy), The History of Rome, Book 2
Benjamin Oliver Foster, Ph.D., Ed.

5. The question of the royal property, which they had before voted to return, was laid before the Fathers for fresh consideration. This time anger won the day. [2] They refused to return it, and refused to confiscate it to the state, but gave it up to the plebeians to plunder, that having had their fingers in the spoils of the princes they might for ever relinquish hope of making their peace with them. The land of the Tarquinii, lying between the City and the Tiber, was consecrated to Mars and became the Campus Martius. [3] It happened, they say, that there was then standing upon it a crop of spelt, ripe for the harvest. Since this produce of the land might not, for religious reasons, be consumed, the grain was cut, straw and all,¹ by a large body of men, who were set to work upon it simultaneously, and was carried in baskets and thrown into the Tiber, then flowing with a feeble current, as is usually the case in midsummer. [4] So the heaps [p. 233]of grain, caught in the shallow water, settled down² in the mud, and out of these and the accumulation of other chance materials such as a river brings down, there was gradually formed an island. Later, I suppose, embankments were added, and work was done, to raise the surface so high above the water and make it strong enough to sustain even temples and porticoes. [5] When the chattels of the princes had been pillaged, sentence was pronounced and punishment inflicted upon the traitors —a punishment the more conspicuous because the office of consul imposed upon a father the duty of exacting the penalty from his sons, and he who ought to have been spared even the sight of their suffering was the very man whom Fortune appointed to enforce it. [6] Bound to the stake stood youths of the highest birth. But the rest were ignored as if they had been of the rabble: the consul's sons drew all eyes upon themselves. [7] Men pitied them for their punishment not more than for the crime by which they had deserved that punishment. To think that those young men, in that year of all others, when their country was liberated and her liberator their own father, and when the consulship had begun with the Junian family, could have brought themselves to betray all —the senate, the plebs, and all the gods and men of Rome —to one who had formerly been a tyrannical king and was then an enemy exile! [8] The consuls advanced to their tribunal and dispatched the lictors to execute the sentence. The culprits were stripped, scourged with rods, and beheaded, while through it all men gazed at the expression on the father's face, where they might clearly read a father's anguish, as he administered the nation's retribution. [9] When the [p. 235]guilty had suffered, that the example might be in³ both respects a notable deterrent from crime, the informer was rewarded with money from the treasury, emancipation, and citizenship. [10] He is said to have been the first to be freed by the vindicta.⁴ Some think that even the word vindicta was derived from his name, which they suppose to have been Vindicius. From his time onwards it was customary to regard those who had been freed by this form as admitted to citizenship.