Population Crises and Population Cycles

The central position of Rome in Italy and Italy in the Mediterranean enabled the independent farmers of the Roman Republic to form a league of Italian states and conquer the population-crisis-ridden societies of North Africa, much of Western Asia, the Aegean, and finally the divided tribes of half-civilised Gaul and Britain. By 167 BC, Rome had extracted some eighty tonnes of gold from the dry belt, and sums of this order came in annually when the Empire was established. This enormous wealth in loot and taxes enabled Rome to develop a brilliant civilisation with a wonderful literature and an impressive legal system. But, perhaps uniquely in history, this coincided with a grave population crisis in Italy, which set in at once as a result of very rapid population growth. The height of overpopulation was reached in the city of Rome itself, which passed the million mark by the end of the 1st century BC (Table 1). 80% of the city population were ex-slaves from all over the Empire, housed in ten-storey wooden fire-traps at a density twice that of modern Paris, who developed a mass culture, in which the first use for the new invention of blown glass was the mass production of mugs stamped with the names of favourite gladiators. The population crisis in Italy lasted for some three centuries (Table 2), during which the republic was replaced by a monarchy. In this unique combination of renaissance and crisis, it was typical that Cicero, who created the vocabulary of Western civilisation, was twice forced into exile, had his house burned down, and was finally murdered.

By the late 1st century AD, the dry belt provinces of the Roman Empire had recovered from their prolonged crisis, and at first the resulting revenue increase also benefited Rome itself, where housing conditions were temporarily improved after the great fire of AD 64. For half a century, there was a relief period. But continued population growth (e.g. Figure 3 of Paper 4 in the June Newsletter) led to devastating crisis (Table 3), with a notable decline in culture and art. In about AD 210, the brilliant Christian writer Tertullian observed that human numbers were a burden to the earth, which could now hardly support them, and that famine, epidemics and wars were the means of cutting back excessive human population growth. In the 4th century AD there was some recovery, but only at the cost of the Empire becoming largely a hydraulic society, with distinctions between slaves and free workers disappearing. A final truly catastrophic crisis in the 6th century AD culminated in the plague pandemic of AD 542-3, which killed 40% of the Empire’s population, and ended Latin and classical Greek as living languages.

By the late 3rd century AD, the dry belt surplus wealth that had supported Roman civilisation had drifted back to North Africa and Western Asia, where the surplus was actually produced and where trade with the Far East was concentrated: ‘much more than half of the silver and much more than two thirds of the gold which had circulated in Roman territory... had left the [Northern] Mediterranean world’ (Fritz Heichelheim, 1956). By then, Italy had lost its privileges, and the effective capital shifted to Nicomedia in (modern) Turkey and then to Constantinople. In AD 476 the Western Empire disintegrated into barbarian kingdoms, and the population shrank back to the low level permitted by the local surplus. In the East, the Byzantine Empire, now a totally hydraulic state, went through several vicissitudes and population cycles before its conquest by the Turks in AD 1453.

Except in Greece, the Northern Mediterranean environment was little damaged in ancient times. When Europe recovered from its Dark Ages, the countries of the region remained important cultural centres until the late 15th century AD. But then incipient population crisis brought to power in Spain a gangster group of transhumant sheep-owners, the Mesta. This Mafia-like organisation ruled Spain for over two centuries, with its Murder Incorporated branch, the Spanish Inquisition (their personnel overlapped). With the Inquisition to eliminate its opponents, the Mesta destroyed most of Spain’s forests and farmlands. Well might Don Quixote mistake the sheep flocks for armies! In Southern Italy, since the 13th century AD, transhumant sheep-rearing had been encouraged by rulers for its tax yield, but the damage vastly increased when the region was totally controlled by Spain after 1504, with even more sheep than in Spain itself (Table 4). By the 18th century AD, the Northern Mediterranean countries were backwaters.

In the 19th century AD, these countries began to revive, by benefiting from the achievement of North-Western Europe (including Northern Italy), the subject of our next paper. But as poor relations they also suffered from pollution export, and later from mass tourist development. The swollen growth of modern Athens (Table 5), now one of the world’s most polluted cities, was produced by foreign investment, starting in the 1920s. By AD 1973, a conference of Mediterranean states showed the whole region to be in a desperate state of pollution and environmental devastation. The success of plans to improve the situation will depend on the achievement of very substantial reduction, by voluntary birth control, of the populations of this region, to whose past glories and grandeurs so much is owed by human civilisation.