he end of this period of expansion the city had a
population of at least half a million, rivalling Alexandria and Antioch,
the great Hellenistic capitals. Although not a manufacturing city, Rome
had always been important as a market, and now her streets were thronged
with traders from all lands, and with persons who could cater in any way
to the wants and the appetites of an imperial city. There was a large
proportion of slaves belonging to the mansions of the wealthy, and of
freedmen engaged in business for themselves or for their patrons. Hither
flocked also the peasants who for various reasons had abandoned their
agricultural pursuits to pick up a precarious living in the city or to
depend upon the bounty of the patron to whom they attached themselves.
Owing to the slowness of transportation by land and its uncertainties by
sea, the congestion of population in Rome made the problem of supplying
the city with food one of great difficulty, since a rise in the price of
grain, or a delay in the arrival of the Sicilian wheat convoy would bring
the proletariat to the verge of starvation. And upon the popular
assemblies the presence of this unstable element had an unwholesome
effect. Dominated as these assemblies were by those who resided in the
city, their actions were bound to be determined by the particular
interests and passions of this portion of the citizen body. Furthermore,
in the _contiones_ or mass meetings for political purposes, non-citizens
as well as citizens could attend, and this afforded a ready means for
evoking the mob spirit in the hope of overawing the Comitia. This danger
would not have been present if the Roman constitution had provided
adequate means for policing the city. As it was, however, beyond the
magistrates and their personal attendants, there were no persons
authorized to maintain order in the city. And since the consuls lacked
military authority within the _pomerium_, there were no armed forces at
their disposal.

*The equestrian order.* The Roman custom of depending as much as possible
upon individual initiative for the conduct of public business, as in the
construction of roads, aqueducts and other public works, the operation of
mines, and the collection of taxes of all kinds, had given rise to a class
of professional public contractors--the _publicani_. Their operations, with
the allied occupations of banking and money-lending, had been greatly
enlarged by the period of war and conquest w