# Popular Science Monthly/Volume 69/December 1906/Vesuvius During the Early Middle Ages

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* VESUVIUS DURING THE EARLY MIDDLE AGES
By Dr. CHARLES R. EASTMAN
HARVARD UNIVERSITY
IT is certain that Vesuvius, prior to the Plinian eruption of 79 A. D., by far the most tragic, and one of the three most violent in Italian history, was regarded as an entirely extinct volcano. The details of this eruption, the sequence of its phenomena, and its peculiarly destructive effects, are familiar to us from contemporary sources, and from the memorials written in large characters by the mountain itself over the ruined cities at its base. From the date cf this catastrophe onward for over fifteen hundred years, when the period of modern investigation begins, our knowledge of Vesuvian history depends upon more or less casual mention, and upon brief notices of eruptions in monastic chronicles.
Owing to the scantiness of our information, little attention has been paid by students to the long interval separating the two most violent paroxysms known to have shaken the mountain. Yet, inadequate as the records are, their importance is of the first order. They register for us the dates of major disturbances, at least, extending over a period of sixteen centuries, and afford some means for estimating the intensity of volcanic action in the Naples district for a still longer period. Moreover, they furnish data for reconstructing the probable form of the mountain in antiquity, and for detecting the amount of change it has undergone since Plinian times. Nor should it be forgotten that the early topographic descriptions that have come down to us offer interesting points of comparison with the present condition of the stately guardian of the Bay of Naples.
Thus it appears that the original sources of information, which are all that need concern us in the present article, acquaint us not only with the actual history of Vesuvius since the first century of our era, but, taken in connection with other facts, throw a fresh coloring upon the accounts of the 'burnt mountain' that have survived from classic times. Two of the points just enumerated will repay further inquiry: first, the chronology of eruptions during the early middle ages; and secondly, the probable form of Somma-Vesuvius in antiquity. One reason why a review of the chronology seems desirable is because the dates of medieval eruptions are often confused, and the authorities for them incorrectly given, or more frequently omitted. It will be profitable, therefore, to take a brief survey of the original sources, but without ​entering into the voluminous literature of the Plinian disaster, which belongs in a separate category. Note, however, that some of the titles included under it are luminous for an understanding of early Somma-Vesuvius history, and the same may be said of Cassius Dio's account of the second eruption (203 or 204), which also falls outside the period of our inquiry.
The whole history of Italy under the Goths is contained in Cassiodorus and Procopius, although the dry compendium of Marcellinus Comes is not without value for the chronology of certain facts. These three writers are our only informants of the eruption that fell at the beginning of the dark ages, in 472, and a word or two concerning them may not be inapt. Magnus Aurelius Cassiodorus, a great Roman noble of wealth, learning and astute statesmanship, born in 480 and reputed to have lived nearly a century, occupies a position throughout the reign of Theodoric scarcely less prominent than that of the king himself, whose chief counsellor he was. His writings, especially the 'Variæ,' or collection of state papers, are of incalculable value for Italian history under Gothic rule, and contain a wealth of curious detail concerning political, social and moral conditions, and general life of the period. In these official papers, the secretary frequently intersperses comments, from an obviously personal point of view, upon any subject that interests him, often displaying remarkable erudition. One of his marked tendencies is a passion for natural history, which he touches upon with naïve ardor, yet displaying withal acute observation. Many a random note occurs relating to birds, beasts or fishes, as witness for example his excursus on the elephant, faintly suggestive of Ctesias, or his description of the 'exormiston,' identified by Dr. Theodore Gill with a Leptocephalus. Little wonder, is it, therefore, that we find in these 'Variæ' (iv., 50) an interesting digression on Vesuvius, apropos of an eruption commonly assigned to the year 512, but which, according to Mommsen, must have taken place from one to five years earlier. The date of this event is accordingly best written 507/511. Allusion is also made to the far more severe eruption of 472, remarkable for its heavy discharge of ashes, carried to an enormous distance. For years afterward at Constantinople a solemn fast was held on the sixth of November in memory of that day when the heavens were darkened, and the greater part of Asia Minor was rocking with frightful earthquake shocks. In another letter (iii., 47) he refers to an eruption of one of ​the Lipari Islands, the date of which is said to have coincided with Hannibal's death, 183 B. C.
So far Cassiodorus. In Procopius (fl. 495-565) we are confronted with a very different sort of personage, yet one recognized as chief authority for the events of the reign of Justinian. His position in literature is defined by Hodgkin, in his 'Italy and her Invaders,' in following terms:
Such appears to be a conservative estimate of Procopius the Cæsarean. He has transmitted to us a vivid pen picture of Vesuvius as observed by him during a four months' sojourn at Naples in 537, at which time an eruption was threatened, though none actually occurred until nearly a century and a half thereafter. Thus it happens that the value of Procopius lies in his excellent topographic description (de Bello Gothico, ii., 4), together with hearsay accounts of the two preceding disturbances (ibid., iii., 35). One of the features of the last which we gather from him is that ashes were carried as far as Tripoli. Lava flows are distinctly mentioned both by him and by Cassiodorus as an accompaniment of these eruptions, a fact often overlooked by modern geologists. The Byzantine historian will have further claim to our attention later on.
Following close upon the fall of the Gothic kingdom came the Lombard invasion, which marks the most ill-starred period of Italian history. But little direct and contemporary testimony to historical facts has come down to us from the Lombards, but as their rule approached its end, a native historian arose who preserves the memory of foreign mastery, and ranks as the most distinguished writer of this early part of the middle ages in Italy. This historian is Paul the Deacon (720-c. 787), to whom we are chiefly indebted for a history of the Lombards and a revision of Eutropius. Both of these writings contain mention of Vesuvian eruptions, and it is interesting to note that we find in them the earliest suggestion that the original Somma crater had been shattered by the Plinian catastrophe. Paulus Diaconus, in his 'Historia Langobardorum,' and the Roman 'Liber Pontificalis,' a compilation due to many hands and extending over a number of ​centuries, are our only sources relating to the ash-eruption of 685, which continued 'mense martio per dies aliquot.' This is reckoned as the fifth in the list of recorded disturbances.
There now ensues a period of dire poverty in Italian chronicles, and we hear nothing further of Vesuvius for nearly three hundred years. Then are found meager and incidental notices of two eruptions, during the earlier of which lava flows reached the sea, a symptom of high intensity, only twice repeated in modern times. The unique authority for these events is Petrus Damianus, a prolific and most singular polemical writer of the early eleventh century, monk and cardinal, whom Balzani describes as having 'treated in prose and verse every possible subject, whether in literature, homilies, lives of saints, political or religious treatises. Some confusion exists regarding the dates of these eruptions. This arises from the fact that the years in which they occurred are unmentioned, although names are given instead of petty princes with whose deaths they synchronized, the coincidence being interpreted in a manner usual to the times. Later on we find an extract of Peter's account appearing in a postscript to Leo of Marsi's 'Chronicon' under date of 1049, where, unfortunately, the name of the reigning duke of Naples, John III., is omitted, thus leaving it uncertain which one of the numerous family of Capuan princes was intended. Recently the tangle has been unraveled by the Neapolitan historian Capasso, who is no doubt correct in assigning the events in question to the years 968 (in lieu of 982) and autumn of 999, respectively. By a fortunate chance, the original draft of Leo of Marsi's chronicle is still preserved at Munich, and, with its erasures and numerous additions, clearly shows what use was made by the author of his materials in preparing finished copy.
For a brief mention of the eighth recorded eruption we are indebted to a wandering monk, Rodulphus Glaber, of whom little is known except that he lived at various monasteries, including those of Bèze and Cluny, after having traveled extensively in Italy. His history, published 1047, is not without value for contemporary events, and is regarded as reliable in the main, hence no reason appears for doubting his account of a violent eruption in 1007. By some authors the passage has been understood to read seven years before instead of after the millenium, hence the earlier date is often incorrectly given in catalogues of eruptions. Mabillon recalls that the year 1006 was
memorable for a number of calamitous happenings, and suggests that the injury wrought by Vesuvius of which Rodulphus informs us may have fallen properly about that time. Bombs were projected on that occasion to a distance of three miles, issuing from a greater number of orifices than usual, and the noxious gases accompanying the eruption rendered the country round about uninhabitable.
An interval of thirty years ensued before the ninth eruption (1037), which was succeeded by a little over a century's repose. After 1139 no further disturbance is known to have taken place until early in the sixteenth century, although Mount Epomeo, in the neighboring island of Ischia, was active in the year 1302. Brief records of the ninth and tenth eruptions are found in monastic chronicles, compiled in near-by abbeys, and of noteworthy importance. Foremost should be mentioned the monastic histories written during the eleventh century at Monte Cassino, a famous abbey of ancient foundation and mother of all Benedictine monasteries, which shone like a light in the dark ages. Of
​interest for our present purpose are the 'Annales Casinenses' (1000-1212), a compilation by various monks whose names are unknown; the 'Chronicon Casinensis' of Leo of Marsi, better known, after becoming
​Bishop of Ostia, as Leo Ostiensis, one of the most sober and important of Italian historians; the 'Annales Cavenses' (569-1318), produced by another famous monastery near Salerno; and finally the 'Chronicon' (1102-1140) of Falco of Benevento, notary, judge and papal chancellor, to whom posterity is indebted for precious information. These contemporary sources contain all that is known of the ninth and tenth Vesuvian eruptions. Details are wanting, but it is said of the former that it happened in January, 1037, and lava flows reached the sea; the duration of the latter (1139) is stated in one account to have been eight, in another, forty days. Critical estimates of the documents above referred to will be found in various works dealing with the sources of medieval history, amongst which it will be sufficient to mention an article by Hirsch on 'Desiderius of Monte Cassino.' Our review of the chronology of eruptions in the early middle ages is now completed.
There remains to be considered a question that has often been asked, and variously answered: was the form of Somma-Vesuvius essentially the same in antiquity as we know it to-day, or were the ancients acquainted with only a single crateriform summit whose broken wall now partially encircles the newer cone? The only reason for raising the inquiry at all is that neither by direct statement nor by implication do any of the ancient authors allude to Vesuvius as a double-peaked mountain, and the older topographic descriptions can with difficulty be reconciled with the present form of the volcano. It appears indeed passing strange that Strabo, Pliny, Cassius Dio and Procopius should all have remained silent respecting the most salient feature of Vesuvius as viewed from the west, in case its twin peaks presented to their eyes, as they do to ours, almost identical outlines. Yet, accepting their accounts at face value, the only conclusion possible is that the younger cone has been entirely built up during the middle ages, a far shorter interval than is demanded by geologic evidence. A time allowance of barely a thousand years (or at the most fifteen hundred, if we leave Procopius out of the reckoning and admit the correctness of Leone di Ambrogio's figure of a double summit in 1514) for the formation of the central cone is absurdly inadequate, the number of eruptions contributing towards it too few, and their intensity too slight, to have performed the work. This we know from the present slow rate of accumulation, and from the relatively unimportant changes wrought by even paroxysmal eruptions. And it may well be doubted whether the convulsion of 79 A. D. was of more violent character than those of 1631 and 1906, these three exceeding all others in intensity.
Fig. 4. Attempted Restoration of the Parthenopian Volcano as it appeared in Strabo's Time. After Pellegrino, 1651. (The site of Veseri is conjectural.)
The problem of the geologist is to determine the past condition of things from what he is able to find out from the present. Nevertheless, the tendency of popular opinion has been to subordinate geologic to documentary evidence, and the majority of standard works continue to uphold the view that Vesuvius proper was non-existent at the time Herculaneum and Pompeii were overwhelmed. As positive a statement of this view as any is the following, from Professor Phillips' excellent work on 'Vesuvius':
Equally confident is the tone assumed by Professor Judd, in his volume on 'Volcanoes' in the International Science Series:
The above description is reinforced by a figure of a truncate colossus, supposed to represent Vesuvius in the time of Strabo, a graphic portrayal that has been popular ever since the first attempt in this direction was essayed by Camillo Peregrino, in 1651. Strange as it may seem, some writers have been misled into supposing that such was the actual form presented by the mountain in the middle of the seventeenth century. As a matter of fact, all these fanciful restorations of the Somma form of crater, however cleverly they may interpret geological evidence, and to that extent suggest remote prehistoric conditions, can not be considered as having any real historical foundation. For we have no right to interpret literary documents in a manner wholly discordant with what is known of the structure and behavior of the mountain itself, but rather should first seek to establish their credibility by scrutinizing them in the light of ascertained facts. If it has been easy to misconstrue Braccini's account of the crater in the first quarter of the seventeenth century, should we not be wary of accepting the usual rendering of ancient authors? And who is so bold as to claim that the huge truncate cone of which Strabo is commonly understood to speak finds any visible support in Pompeiian wall frescoes, of which several representing Vesuvius in a more or less idealized fashion have been discovered? Impressionistic as all of these paintings are, it is not difficult to perceive that the local scene which caught the artist's fancy was after all not very different from that which still meets our gaze from within or hard by the disinterred city.
We may affirm, then, this conclusion: there is no good reason to suppose that Vesuvius appeared materially different in the yesterday of one or two thousand years ago than it does to-day. The summit of the younger cone, still partially encircled by the ancient Somma rim, has been undergoing comparatively slight modification throughout probably the whole course of human history. And we must perforce believe it to have been existent even before the race of man had appeared on the face of the earth, and had begun to acquire dominion over it.
* ↑ Pious imagination of later days has added much fanciful embroidery to the accounts of this and other early eruptions, coupled with the miraculous intervention of Naples' patron saint. The curious will find entertaining reading in the various lives of St. Januarius, as, for instance, that by Girolamo, 1733.
* ↑ 'Monumenta Germaniæ Historica, Auct. Antiq.,' Vol. XII. (1894), p. 137. We shall refer hereinafter to the folio volumes of the 'Scriptores' series under the abbreviation M. G. H., SS.
* ↑ 'Hist. Lang.,' edited by Muratori, R. I. S., Vol. V., p. 59.
* ↑ Ugo Balzani. 'Le cronache italiane nel medio evo.,' 2d ed. (Milan, 1900). The complete works of Petrus Damianus are edited by Migne, 'Patrolog. lat.,' Vols. CXLIV., CXLV. (Paris, 1853). Cf. Opusculis xix., c. 9 et 10.
* ↑ B. Capasso, 'Monumenta Neapolitani Ducatus,' Vol. I., p. 114. For an account of the Pandulf line of princes, see the article by M. Schipa in Archiv. Storico Prov. Napoletane, ann. XII. (1887), p. 254, and compare the genealogical table given in Pflugk-Harttung's 'Iter Italicum,' p. 711.
* ↑ M. G. E., SS., Vol. VII., p. 61.
* ↑ M. G. H., SS., Vol. XIX., pp. 306, 309.
* ↑ Ibid., Vol. VII, pp. 670, 684.
* ↑ Ibid., Vol. III., p. 189.
* ↑ Murateri, R. I. S., Vol. V., p. 128.
* ↑ Forsch. deutsch. Gesch., Vol. VII., 1867, pp. 1-112.
* ↑ 'Discorsi della Campania Felice,' p. 309. (Naples, 1651.)
* ↑ For a recent and interesting discussion of this whole matter, and also of the events of the Plinian eruption, one may consult the following: Enrico Cocchia, 'La forma del Vesuvio,' an essay reprinted in Volume III. of his 'Saggi Filologici' (Naples, 1902); and S. Herrlich, 'Die antike Ueberlieferung liber den Vesuv-Ausbruch im Jahre 79.' Beitr. zur alten Gesch.,Vol. IV. (1904), pp. 209-220.