732 THE AMERICAN JOURNAL OF SOCIOLOGY
themselves from the attacks of pirates, which led the early settlers of Athens to remain at a distance of some five miles from the sea, was equally powerful in the case of Rome. At a distance of some fourteen miles from the mouth of the Tiber the series of surrounding hills furnished a readily defensible position most favorable to permanent settlement.
The founding of the city has been lost in a mass of legend and tradition. It is quite certain, however, that a number of separate tribal settlements existed on the several hills long before the formation of a unified city. The division of the city into wards, known as tribus rusticcB, long after such unity had been attained, is conclusive evidence of the nature of the con- stituent factors in the formation of the city. The explanation now generally accepted is that the necessities of common defense forced the tribes into closer relationship, which ulti- mately developed into political unity. The first organization of the populus romanus is in the three tribes — the Ramnes, the Titles, and the Luceres — which were probably the original tribal settlements.
The cities of ancient Italy, while lacking the charm of high artistic development which characterized some of the cities of Greece, mark a distinct advance when viewed from a political standpoint. The Greek concept of restricted city territory was ill-adapted to the larger view of political relations developed by the Romans. Furthermore, the growth of a world-empire made it necessary to give a broader interpretation of citizenship. Roman citizenship was conferred upon the leading citizens of conquered districts, even when situated at great distance from the city. This intangible political relation marked a long step toward the idea of nationality. Of all the cities of the Italian peninsula of this period Rome is the only one which commands our attention because of its enormous influence upon western civilization, the magnitude of the municipal problems with which it had to deal, and the striking analogies with modern urban growth. In her history one can detect the presence of most of the forces which explain the increase of urban population in recent times. In advancing beyond the "city-state" and developing the idea of
