The African-European-Asian triangle was a meeting place and a battle ground. Phoenician and Greek cities brought to this scene new factors and new forces: the rudiments of science; trade and commerce, including a money economy, accounting and cost keeping; the elements of economic organization; the conduct of public affairs by governments based on law rather than on the whim and word of a deified potentate; and the construction of cities and city states built on these foundations. Rome entered the picture when the forces of political absolutism based upon an agriculture operated by serfs and slaves had fought themselves to a standstill and exhausted their historical usefulness. The times called for new forces capable of adapting themselves to a new culture pattern extending over a greatly enlarged world. The Romans, with their Greek associates, were in a position to fill the gap. Romans lived originally in Latium, a small land area in southern Italy on the Tiber River far enough inland to be protected against pirates. They built a city which finally covered seven adjacent hills and developed a community of working farmers, merchants, craftsmen and professionals. The farms were small, averaging perhaps eight to fifteen acres, an area large enough to provide a family with a stable though meagre livelihood. The farmers were hard working and frugal. At this period of Roman history and mythology Latium was one of many communities occupying Italy. Each was self-governing. Each took the steps necessary for survival and expansion. Like their neighbors, the inhabitants of Latium were prepared to defend themselves against piracy, brigandage and ambitious, aggressive rivals. Defense took the form of an embankment and a water-filled moat which surrounded the early settlements and provided shelter for herdsman and farmers in case of emergencies. At some point in pre-history, presumably when Etruscan princes were in control of Roman affairs, the protective earth embankment which surrounded the Roman settlements was strengthened by building a moat 100 feet wide and 30 feet deep. Behind the moat was a stone wall 10 feet thick and 30 feet or more in height. Parts of this defense were built and rebuilt at various times. When completed they were about six miles in length, enclosing an area sufficient to accommodate the chief buildings of the city and living space for a population of perhaps 200,000 people.