On this site, which once had been crowded only when the Roman farmers had taken refuge within the walls with their families, flocks, and herds on the threatening appearance of an enemy, by the time of Cicero an enormous population had gathered. Many causes had combined to bring this population together, which can be only glanced at here. As in Europe and America at the present day, so in all the Mediterranean lands since the age of Alexander, there had been a constantly increasing tendency to flock into the towns; and the rise of huge cities, such as Antioch, Alexandria, Carthage, Corinth, or Rhodes, with all the inevitably ensuing social problems and complications, is one of the most marked characteristics of the last three centuries B.C. In Italy in particular, apart from the love of a pleasant social life free from manual toil, with various convenient resorts and amusements, the long series of wars had served to increase the population, in spite of the constant loss by the sword or pestilence; for the veteran soldier who had been serving, perhaps for years, beyond sea, found it hard to return to the monotonous life of agriculture, or perhaps found his holding appropriated by some powerful landholder with whom it would be hopeless to contest possession. The wars too brought a steadily increasing population of slaves to the city, many of whom in course of time would be manumitted, would marry, and so increase the free population. These are only a few of the many causes at work after the Punic wars which crammed together in the site of Rome a population which, in the latter part of the last century B.C., probably reached half a million or even more.[16] Let us now descend from the Janiculum, and try to imagine ourselves in the Rome of Cicero's time, say in the last year of the Republic, 50 B.C., as we walk through the busy haunts of this crowded population. We will not delay on the right bank of the Tiber, which had probably long been the home of tradesmen in their gilds,[17] and where farther down the rich were buying land for gardens[18] and suburban villas; but cross by the Pons Aemilius, with the Tiber island on our left, and the opening of the Cloaca maxima, which drained the water from the Forum, facing us, as it still does, a little to our right. We find ourselves close to the Forum Boarium, an open cattle-market, with shops (tabernae) all around it, as we know from Livy's record of a fire here, which burnt many of these shops and much valuable merchandise.[19] Here by the river was in fact the market in the modern sense of the word; the Forum Romanum, which we are making for, was now the centre of political and judicial business, and of social life.