Malaria and Rome: A History of Malaria in Ancient Italy
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In another passage (4.547), on the foundation of Constantinople, William noted that the emperor Constantine sought a healthy location for his new city because he could not tolerate the Mediterranean sun, having been born in Britain. Cicero Letters to Atticus 236.2–237.2, ed. Shackleton-Bailey (1965–70); Celli (1933: 82).
¹⁷ Cicero Letters to Atticus 153.4: Apulia delecta est, inanissima pars Italiae; Varro, RR 2.1.16
and 2.9; Sanpaolo (1995: 87–91) on the archaeology of transhumance; Compatangelo-Soussignan (1994) on crop production in Apulia.
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Apulia
malaria in the lowlands, since the animals went into the hills in summer, the time of the year when female mosquitoes are searching for prey. However, he believed that the maintenance of domestic animals in close proximity to the human agricultural population in the lowlands could reduce malaria by deviating mosquitoes away from humans.¹⁸
¹⁸ Falleroni (1921).
11
Geographical contrasts and demographic variation
The comprehensive evidence of the English parish studies discussed in Chapter 5. 4 above confirms the evidence derived from scattered local studies in Italy, such as the comparison between Grosseto and Treppio first mentioned in Chapter 1 above. Malaria, even the relatively mild P. vivax, enormously increased mortality levels, sharply reduced life expectancy at all ages, and significantly altered the age-structures of human populations in Europe in the past, wherever it became endemic. However, occurrences of malaria tended to be highly localized because of the very complicated ecological requirements of the disease, as, for example, at Old Salpi, where just by moving a few kilometres away the environment became much healthier. Consequently malaria generated enormous regional variations in demographic patterns in early modern Europe. In view of the compelling evidence from ancient sources for the endemicity in large areas of central and southern Italy of all three species of human malaria under consideration here, the comparative evidence from early modern Europe suggests that such major regional variations in demographic patterns should also have occurred in Roman Italy. There is no doubt whatsoever that that is exactly what happened. Pliny the Younger testifies to it, in a fundamental text whose neglect by those historians who have chosen to specialize in studying the demography of the ancient Roman world simply demonstrates their failure to understand the demography of Roman Italy. It is necessary to return again to the comparison of Pliny’s villas near Laurentum in Latium and near Tifernum in Umbria. Laurentum was uncomfortably close to some of the most malarious places on earth.¹ Not far away ¹ It is quite possible that there were healthy localities in the vicinity, bearing in mind the description of Laurentum in the late second century given by Herodian 1.12.2, since the distribution of malaria was always highly localized. Nevertheless Pliny’s own comments on the gravis et pestilens ora Tuscorum (oppressive and pestilential coastal region of Tuscany) leave no doubt that Laurentum in his own time was not far from extremely unhealthy areas.
Blewitt (1843: 529) described the Laurentine forest in the nineteenth century. He noted that ‘the proper season for enjoying a residence at Castel Fusano is the spring; in summer it 270
Geographical contrasts
lay the silva Laurentina, doubtless in parts a flooded forest in winter like the Pontine forest further south along the coast, since ancient authors describe it as a large marsh, the haunt of wild boars.²
Almost certainly it was a malarial marsh. If it had not been so, Vitruvius would have cited it instead of Ravenna as a case of a healthy marsh much closer to the city of Rome than Ravenna. The presence of intense malaria explains the virtual abandonment of Laurentum during the time of the Roman Empire, a state of affairs that lasted right through to the end of the nineteenth century .³
In contrast, Tifernum, as described by Pliny, was cold and frosty in winter, with a temperate and windy climate in summer.⁴ It was too cold for the olive tree, whose geographical distribution corresponds to Mediterranean-climate regions, to grow there. It was also too cold for P. falciparum and its principal vector in Italy, A. labranchiae.
Pliny clearly observed the demographic consequences, an abundance of elderly people: Here there are many elderly people: you can see the grandfathers and great-grandfathers of young men and hear old stories and discussions about ancestors, and when you come here, you think that you have been born in another age.⁵
It has been frequently suggested by modern historians that only a small proportion of Romans would have had surviving fathers or grandfathers by the time they reached adulthood themselves; Tifernum, at least, was one Roman community where that theory is false. Undoubtedly there were numerous other communities like it, in the more mountainous parts of Italy along the Apennines.
Pliny emphasized the healthiness of Tifernum, stating that he had swarms with mosquitoes, and is not free from the suspicion of malaria’. [Aurelius Victor,]
Origo gentis Romanae 12.4, ed. Richard (1983), mentioned the duo stagna aquae salsae vicina inter se (two swamps with salty water near each other) close to the spot where Aeneas is supposed to have landed in Italy, although the reference perhaps should be to the salt marshes of Ostia instead of Laurentum (commentary in Richard’s Budé edn., pp. 149–50 n. 9), cf. Velleius Paterculus 2.19.1.
² Virgil, Aeneid 12.745, cf. 10.707–12. Quilici (1979: 65–6, 78, 81).
³ The rus vacuum (empty countryside) predicted by Lucan, de bello civili 7.394–5.
⁴ Defosse (1981) discussed the climate of Tifernum. Climate warming can be associated with an increase in the degree of climate variability, as is probably happening at the present time. Consequently the occasional occurrence of cold winters attested by Pliny does not necessarily contradict other evidence that the time of the Roman Empire as a whole was a warm period (see Ch. 4. 5 above).
⁵ Pliny, Ep. 5.6.6, ed. Schuster (1958): hinc senes multi, videas avos proavosque iam iuvenum, audias fabulas veteres sermonesque maiorum, cumque veneris illo, putes alio te saeculo natum.
Geographical contrasts
271
not lost any of the members of his household whom he had brought with him. There is an implicit contrast with two other places where he spent much of his time, Laurentum and Rome, where he was presumably not so fortunate:
also my slaves have never lived in a healthier environment: so far I have not lost any of those whom I brought with me⁶
The contrast between Tifernum, on the one hand, and Laurentum and Rome on the other, in antiquity, is a typical example of the extreme regional variation in demographic patterns which is now known to have been the norm in early modern Europe. It exactly parallels the contrast made by del Panta between Treppio and Grosseto in the nineteenth century, for exactly the same fundamental reason, namely the absence or presence of malaria. In a review of a book on medieval demography Johannson made a devastating critique of a series of assumptions that are also frequently made by modern historians writing about the demography of the Roman Empire. She concluded that ‘early modern Europe was characterized by extreme variability with respect to its mortality patterns’, after noting that England in the seventeenth century contained places with life expectancy at birth as high as 50 and other localities with a life expectancy at birth as low as 20, as demonstrated by the parish studies.⁷ These data destroy the view regularly expressed by Roman historians that the Roman population (it would be better to say Roman population s) could not have had a life expectancy at birth higher than 25 or 30. The inhabitants of Tifernum would have been astonished to learn of that hypothesis. Johannson then observed that ‘long-run growth rates of 1% to 2% per year (on average) are not unusual for those villages which were free of malaria, sheltered from frequent epidemics, and spared major famines. In malarial parishes, in contrast, death rates persistently exceeded birth rates’.⁸ This, again, destroys the widely held view among ancient historians that ancient populations could not possibly have grown at more than about 0.5% per annum.
Since the attempt by Lo Cascio to overthrow the Roman demography of Beloch and Brunt depends on such assumptions about life ⁶ Pliny, Ep. 5.6.46: Mei quoque nusquam salubrius degunt; usque adhuc certe neminem ex iis, quos eduxeram mecum . . . ibi amisi.
⁷ Johannson (1994: 528).
⁸ Ibid., 531.
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Geographical contrasts
expectancy and growth rates, and more generally on defining too narrowly what Braudel called ‘the limits of the possible’, it must be regarded as unconvincing in detail. Nevertheless Lo Cascio was right to draw attention to the problems of interpreting the Roman census data, problems which will probably never be completely resolved without the discovery of new evidence.⁹
One of the conclusions of this book is that the figure of 25, commonly assumed by historians as an appropriate figure for the life expectancy at birth of the Roman population, is both too low and too high. Healthy areas could very easily have had substantially higher life expectancy at birth than that. It is worth quoting some of the exact words of Herlihy and Klapisch-Zuber about late medieval Florence to hammer home this point:
About 1300 the average duration of a human life at Florence was approximately 40 years. But over the following 100 years, amid the fury of pestilence [sc. the Black Death], it collapsed to only one half that figure (an average of only some 20 years). In the fifteenth century the average duration of life grew more extended, especially after 1450, to regain the summit of 40 years . . . A perusal of the Florentine family memoirs leaves the impression that men lived to an old age in the thirteenth century.¹⁰
Florence was certainly not unique. In the course of a discussion in which he cited numerous examples of historical populations drawn from all over the world which had a life expectancy at birth significantly higher than 25, the Italian demographer Massimo Livi-Bacci drew attention to research showing that the nobility of Milan had a life expectancy at birth of about 40 in the seventeenth century .¹¹ However, the words of Herlihy and Klapisch-Zuber also illustrate the downside: in an unfavourable disease environment life expectancy at birth could easily be significantly less than 25. The city of Rome during the period of the Roman Empire did not have bubonic plague, but had P. falciparum malaria instead.
⁹ Lo Cascio (1994).
¹⁰ Herlihy and Klapisch-Zuber (1985: 83–4).
¹¹ Livi-Bacci (1983). Historical populations with a life expectancy at birth of more than 25
are now known from all over the world, e.g. Zhao (1997) suggested a life expectancy at birth of about 34 (Coale–Demeny Model East Level 8) for a Chinese clan in the period 1000–1750, relying on data for adult mortality; Farris (1985: 43) suggested life expectancies at birth ranging from 27.5 to 32.5, with growth rates of over 1% per annum, for some villages in Japan in the early eighth century . Barker and Rasmussen (1998: 102) observed that numerous very high ages are recorded on Etruscan funerary inscriptions, although these records are of course not necessarily reliable (Hopkins (1966) ).
Geographical contrasts
273
Once P. falciparum malaria has become endemic, its effects are nowhere near as spectacular as those of a sudden, major epidemic of plague ( Yersinia pestis), such as the Black Death or the plague of Justinian. Nevertheless the depression of life expectancy at birth which it caused in the long run in historical European populations appears to match the magnitude of the effects of plague, since life expectancy at birth in Grosseto in the nineteenth century was apparently not dissimilar to that in Florence during the period of major plague epidemics. Shortly after the end of antiquity, the Rome of Pope Gregory the Great was unfortunate enough to have both bubonic plague and endemic malaria at the same time, the end of the sixth century .¹²
It is now well known, following the work of Roger Mols in the 1950s on European cities and the later classic studies of Wrigley and Finlay on London, that large pre-industrial urban populations were incapable of reproducing themselves. Large cities depended on constant immigration from less densely populated but more healthy rural areas both to maintain and to increase their population sizes. Early modern Rome certainly fitted the same pattern as London. As a nineteenth-century Italian writer put it:
All the great cities . . . like Rome, consume more men than they produce, and are refurnished from the countryside.¹³
Research into the demography of early modern Rome by
Schiavoni and Sonnino showed that the growth of the city of Rome depended on immigration for most of the period of study, from 1598 to 1824. There was a significant excess of deaths over births for most of this period (see Table 9). The exceptional period of low death rates from 1658 to the end of the seventeenth century followed a plague epidemic in 1657, accompanied by extensive migration away from the city to avoid the disease. Subsequently the city’s population was recovering from a very low base. These data show that the Roman population was capable of increasing on its ¹² For bubonic plague ( lues inguinaria) in Rome, accompanying a Tiber flood, at the beginning of the reign of Gregory see Paulus Diaconus, Historia Langobardorum, iii.24, ed. Waitz (1878) Monumenta Germaniae Historica, vol. xlviii ( Scriptores 7) and Gregory of Tours, History of the Franks, x.1, cf. Paulus Diaconus, ii.4, iv.4, and vi.5 for other outbreaks of plague. It should be noted that the vocabulary used to describe plague was completely different from that used for malaria. Consequently there is no chance that the two diseases were confused.
¹³ A. Gabelli, Prefazione, in Monografia (1881: lii): Tutti le grandi città . . . al pari di Roma, con-sumano più uomini che non ne producano, e ne vengono rifornite dalle campagne.
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Geographical contrasts
36. The angel of
death striking a
door during the
plague of Rome in
1656. Engraving by
Levasseur after
J. Delaunay. The
Wellcome Library,
London.
Geographical contrasts
275
Table 9. Baptisms and deaths (per 1000) in Rome from 1621 to 1824
Period
Baptisms
Deaths
1621–9
26.9
38.3
1630–9
30.4
29.0
1640–9
29.7
33.8
1650–5
27.9
31.8
1656–7
26.0
69.3
1658–9
30.8
28.1
1660-9
32.8
24.5
1670–9
30.1
25.6
1680–9
30.0
23.9
1690–9
30.9
24.0
1702–9
27.7
29.7
1710–19
26.0
39.3
1720–9
27.1
38.7
1730–9
28.3
41.1
1740–9
29.4
42.6
1750–9
32.3
39.9
1760–9
31.4
46.5
1770–9
32.6
38.3
1780–9
32.0
46.0
1790–9
33.1
44.9
1800–9
32.8
50.3
1810–19
30.8
37.6
1820–4
33.1
37.4
Source: Schiavoni and Sonnino (1982: 102, table II).
own when it was small. Such a capability of course helps to explain where the manpower for colonization came from in the early stages of Roman history in antiquity. At the same time the early modern data als
o make it clear that as the urban population grew, a deficit of births relative to deaths became inevitable, and inevitable at a population-size level far below the size of the population of the city of Rome during the time of the Roman Empire.
The availability of data from Rome itself in the early modern period means that there is in fact no need at all for historians to rely on the example of London; the data from Rome itself are much more pertinent. Delumeau studied the census of 1526–7 in Rome.
Extrapolating from a sample of about 4,000 people for which evidence is available, he reached the conclusion that out of Rome’s population of about 55,000 at that time, only 16% were actually of local origin. No less than 64% of the population of Rome in 276
Geographical contrasts
1526 originated from other parts of Italy (principally Tuscany—encouraged by the presence in Rome at the time of popes born in Florence—and Milan), while as much as 20% of the population came from outside Italy (mainly from Spain, France, and Ger-many).¹⁴
There is no reason for thinking that ancient Rome was any healthier than early modern Rome. Celsus observed that urbani, the inhabitants of towns, were particularly liable to ill health.¹⁵ Indeed the situation in ancient Rome was probably significantly worse than the situation in early modern Rome, since the population was larger and denser during the time of the Roman Empire, and Galen’s information about the frequency of P. falciparum malaria in Rome in the second century must also be taken into account.
The evidence of Herodian (commenting on the epidemic of 189, probably smallpox¹⁶) confirms that massive immigration to the city of Rome was occurring in Galen’s own time.¹⁷ Even as late as after the capture of Rome by Alaric in 410, it appears that the city was still attracting immigrants, according to Olympiodorus.¹⁸ It was noted in Chapter 5. 4 above that visitors from northern Europe contracted malaria in Rome and took the parasites back home with them. However, it is also very important to observe that continuous immigration to Rome would by itself have intensified malaria in and around the city because undoubtedly some of the immigrants would have come from other areas of endemic malaria (e.g. in southern Italy), already be infected, and so bring new malarial parasites to the city in their bloodstreams. The city of Rome both exported and imported diseases, a role facilitated first in antiquity by increased human mobility following the unification of the Mediterranean countries and a large part of Europe under the Roman Empire, and secondly in subsequent historical periods by ¹⁴ Delumeau (1957: i. 197–220); Black (1789: 17) recognized in the eighteenth century that the birth rate was lower than the death rate in Rome; Sori (1984: 554–9).