Titus Livius (Livy), The History of Rome, Book 1
Rev. Canon Roberts, Ed.

33. After handing over the care of the various sacrificial rites to the Flamens and other priests, and calling up a fresh army, Ancus advanced against Politorium, a city belonging to the Latins. He took it by assault, and following the custom of the earlier kings who had enlarged the State by receiving its enemies into Roman citizenship, he transferred the whole of the population to Rome. [2] The Palatine had been settled by the earliest Romans, the Sabines had occupied the Capitoline hill with the Citadel, on one side of the Palatine, and the Albans the Caelian hill, on the other, so the Aventine was assigned to the new-comers. [3] Not long afterwards there was a further addition to the number of citizens through the capture of Tellenae and Ficana. Politorium after its evacuation was seized by the Latins and was again recovered; and this was the reason why the Romans razed the city, to prevent its being a perpetual refuge for the enemy. [4] At last the whole war was concentrated round Medullia, and fighting went on for some time there with doubtful result. The city was strongly fortified and its strength was increased by the presence of a large garrison. The Latin army was encamped in the open and had had several engagements with the Romans. [5] At last Ancus made a supreme effort with the whole of his force and won a pitched battle, after which he returned with immense booty to Rome, and many thousands of Latins were admitted into citizenship. In order to connect the Aventine with the Palatine, the district round the altar of Venus Murcia was assigned to them. [6] The Janiculum also was brought into the city boundaries, not because the space was wanted, but to prevent such a strong position from being occupied by an enemy. It was decided to connect this hill with the City, not only by carrying the City wall round it, but also by a bridge, for the convenience of traffic. [7] This was the first bridge thrown over the Tiber, and was known as the Pons Sublicius.¹ The Fossa Quiritium also was the work of King Ancus and afforded no inconsiderable protection to the lower [8??] and therefore more accessible parts of the City .Amidst this vast population now that the State had become so enormously increased, the sense of right and wrong was obscured, and secret crimes were committed. To overawe the growing lawlessness a prison was built in the heart of the City overlooking the [9] Forum.

The additions made by this king were not confined to the City. The Mesian Forest was taken from the Veientines and the Roman dominion extended to the sea, at the mouth of the Tiber the city of Ostia was built, salt pits were constructed on both sides of the river, and the temple of Jupiter Feretrius was enlarged in consequence of the brilliant successes in the war.