7. The city was enlarged by Tullus Hostilius,[7] after the destruction
of Alba, and the Viminal hill included within the walls; Ancus Martius
added mount Aventine, and the Esquiline and Capitoline[8] being
enclosed in the next reign, completed the number of the seven hills on
which the ancient city stood.

8. The hill called Jani'culum, on the north bank of the Tiber, was
fortified as an outwork by Ancus Martius, and joined to the city by
the bridge; he also dug a trench round the newly erected buildings,
for their greater security, and called it the ditch of the Quirites.
9. The public works erected by the kings were of stupendous magnitude,
but the private buildings were wretched, the streets narrow, and the
houses mean. It was not until after the burning of the city by the
Gauls that the city was laid out on a better plan; after the Punic
wars wealth flowed in abundantly, and private persons began to erect
magnificent mansions. From the period of the conquest of Asia until
the reign of Augustus, the city daily augmented its splendour, but so
much was added by that emperor, that he boasted that "he found Rome a
city of brick, and left it a city of marble."

10. The circumference of the city has been variously estimated, some
writers including in their computation a part of the suburbs;
according to Pliny it was near twenty miles round the walls. In
consequence of this great extent the city had more than thirty gates,
of which the most remarkable were the Carmental, the Esquiline, the
Triumphal, the Naval, and those called Tergem'ina and Cape'na.

11. The division of the city into four tribes continued until the
reign of Augustus; a new arrangement was made by the emperor, who
divided Rome into fourteen wards, or regions.[9] The magnificent