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The Ancient Natural World Part 7

The cause of the obscuration of A.D. 536 remains unknown. The most likely explanation is that it was high-level dust from a huge volcanic eruption. Other suggestions have been the passage of the solar system through a dust cloud, submarine outgassing, or enormous forest fires, possibly ignited by exploding meteors.

If it was a volcano, where was it? Vesuvius 'rumbled' early in A.D. 536, but Procopius says, "it did not break forth in eruption". Mediterranean observers say that the obscuration lasted from a year to 15 months, while further south it lasted 18 months. This suggests that the eruption (if there was one) was further south still, probably in the tropics. There was a huge explosion of the volcano Rabaul on the island of New Britain about A.D. 540. Vast amounts of pumice and ash fell into the sea west of the volcano, and an even larger quantity of ash and sulphuric aerosols, injected into the stratosphere, might have overcast the Mediterranean region within a few weeks.

The shrouded Sun brought cold and drought. Cassiodorus says that the summer was without heat or rain, and chilled by north winds. Snow killed the birds in Mesopotamia. Trees all over the Northern Hemisphere were stunted by cold and drought. Sierra Nevada tree rings show that the years A.D. 535, 536 and 541 were the second, third and forth coldest years in the last two millennia. The rings from Swedish pines indicate that A.D. 536 had the second coldest summer of the last 1,500 years. Drought in China, which was afflicting the north of the country in the spring of A.D. 535, became more severe. Yellow dust from the parched lands swept south, and fell like snow. During the years A.D. 536 to 538 there were summer snows and frosts, drought and famine. In one province seven out of every ten people starved to death in A.D. 536, and the survivors ate corpses.

The suffering inhabitants of the world were not interested in the cause of the obscuration. The natural phenomena of their planet were a trial to them. Storms and earthquakes caused direct hardship, and they found terror, not beauty, in the displays of the sky. Gregory of Tours, watching a glorious crown of auroral light later in the 6th century, wrote, "This extraordinary phenomenon filled me with foreboding, for it was clear that some disaster was about to be sent from heaven." The possibility that such a spectacle might be a gift of God rather than a warning of catastrophe seems not to have occurred to anyone. There were certainly enough catastrophes to be foretold.


The greatest disaster was the Justinian Plague. It was preceded by burning skies, counterfeit Suns, “fiery battles fought in the air”, darkness by day, “and something resembling dust and ashes” which fell from the sky.

There had been previous epidemics in the Roman world. The Antonine Plague, spread by soldiers returning from Seleucia, affected Asia Minor, Egypt and Greece during the reign of Marcus Aurelius. Another plague broke out in Egypt in A.D. 251 and spread through the Empire. Neither of these compared to the Justinian Plague, named after the eastern emperor in whose reign it occurred. This extended over the Roman world, and beyond.

Procopius says that the disease, (which was bubonic plague), reached Constantinople in the spring of A.D. 541 and lasted four months. At its worst 10,000 people died per day. Huge pits, each capable of holding 70,000 corpses, were dug across the Golden Horn, but they were soon filled. Then the towers of the city walls were stacked with dead bodies, creating an all-pervading stench. John of Ephesus says that there were up to 16,000 deaths a day and that the guards of the city gate gave up counting after the 230,000th corpse was carried out. Ships crewed by corpses drifted in the Mediterranean, and terrified sailors reported sea monsters off the coast of Palestine and a ghost ship of bronze rowed by headless oarsmen. Zachariah of Mitylene wrote that the disaster was "a scourge from Satan, who was ordered by God to destroy men."

While the plague raged, earthquakes seemed to multiply. Stricken Constantinople was shaken on August 16, A.D. 542. On September 6, A.D. 543, an earthquake "throughout the known world" destroyed half the city of Cyzicus, near the Hellespont. In AD 545, a wave (probably a tsunami) drowned many in Thrace. From A.D. 546 to 560 Constantinople suffered frequent shocks. On July 9, A.D. 551 the entire eastern Mediterranean was shaken, and cities fell in ruin from Syria to Phoencia. The sea withdrew for miles, then poured over the coast in another seismic sea wave. The next year, it was the turn of Greece, where towns were wrecked by earthquake and a sea wave broke over the coast. On ebbing, it “left innumerable unknown Fishes on the Shore.” At dawn on August 15, A.D. 553 (or 555), shocks began in Constantinople "and many other parts of the world", which lasted 40 days. The city of Berytus (Beirut) was ruined. A.D. 557 was a year ridden with earthquakes. Constantinople, Antioch, Rome and many other cities suffered; there was thunder, lightning, 'subterranean noise' and shooting stars. Part of the church of Hagia Sophia in Constantinople collapsed as "the earth cried out in pain" with "clouds and rolling dust that blazed with fire at noon."


Christianised Europe was losing interest in the physical world. Monks and hermits departed to "desert places and vast solitudes", where they might be as free as possible from its intrusions. They tormented their own bodies, outraged when the crude needs of nature intruded upon the contemplation of spiritual matters. Christianity had its eyes set upon Heaven, and, to the most committed, anything that happened on earth was merely a distraction. Many Christians were convinced, especially after the catastrophe of the Justinian Plague, that the world would shortly end anyway. Ambrose said that Christianity was the crop that came just before the winter frosts. The fall of Rome, which Christian writers said must precede the end of the world, had already happened.

Cosmas map


One Christian who was interested in the natural world was Cosmas Indicopleustes. He was a widely travelled Alexandrian merchant, who may, as his surname indicates, have gone as far as India. He saw two solar eclipses at the Ethiopian port of Adoulis on February 6 and August 1, A.D. 547. (He may have been in the zone of totality of the first, but the second can only have been a very small partial at Adoulis). Cosmas was a pious Christian, who disliked the pagan idea of a spherical revolving Earth surrounded by planetary and stellar spheres. The pagans were in full retreat everywhere. The worship of their gods had become unlawful. Why should a pagan concept of the universe, which Cosmas thought contradicted the Bible, prevail? He found the idea of Antipodes ludicrous; "ye suppose that there are men walking the earth over with their feet opposite the feet of other men…(on) that unstable and revolving mythical sphere of yours."

Cosmas later became a monk and wrote the Christian Topography, which derived all its information about the world from extrapolations of the Bible. His universe was vastly different from the complexities of Ptolemy. It was a rectangular box, "in which are the angels and men and all the present state of existence", with the flat motionless Earth for a floor and the firmament for a roof, closed in on all sides by the walls of the first Heaven. Above the firmament was the vaulted form of the second Heaven, "the kingdom of Heaven into which Christ, first of all, entered."

In the uninhabited north-western region of the Earth was a great conical mountain. When the Sun passed behind it, the mountain cast its shadow over the inhabited Earth and caused night. In winter the Sun, lower in the sky, was hidden by the mountain's wider base and therefore the nights were longer. Cosmas pointed out problems involved with rotating spheres and the contrary movement of the planets, and asked how the pagans' spherical Earth revolves. "Some insist that the sphere rotates like a lathe by the shaft…let these show on what support the shaft and axle rest, and then again on what this support rests, and so on to infinity." If some critic asked on what support Cosmas' Earth rested, he merely replied that Job had said that the Earth hung upon nothing, and that in the Psalms it was said that the Earth is founded upon its own stability.

Cosmas' ideas were probably not influential (his work was unknown in Europe until 1706), although about A.D. 300 the Church Father Firmianus Lactantius had rejected a spherical Earth and the Antipodes on Biblical grounds. Pagan scholars, if there were any left, would have probably considered him a reactionary diehard, going back to ideas that predated Pythagoras. Cosmas disdained them, saying that the theory of a spherical Earth and revolving heavens "is subversive alike to all divine scripture of both the Old and the New Testament, and of Christian doctrine." Nothing more could, or should, be said.


Another Christian writer interested in natural phenomena was Gregory of Tours. Gregory was born in Arverni (now Clermont-Ferrand) in A.D. 538 or 539, and died at Tours in A.D. 593 or 594. He became Bishop of Tours in A.D. 573. He gives vivid descriptions of many phenomena in his
History of the Franks, although he seems to have looked upon all of them with fear, or at least apprehension, and he was a firm believer in portents. Even lights in the sky were portents of death and disaster; but some of the phenomena he describes were not feared as much as they should have been.

In A.D. 563, at the fortress of Tauredunum, on a hillside above the River Rhône in France, subterranean noises were heard for many weeks. They were described as a "curious bellowing sound". These were a portent, but one that went unheeded. After sixty days of warning, the hillside split, separated from the mountain, and slid down in a gigantic landslide. Churches, houses, and people were carried to destruction. The collapse blocked the Rhône, and caused one of the most dangerous of natural phenomena, a thwarted river. The Rhône flowed backwards, rising steadily in its rocky valley. When the valley walls no longer confined it, the river burst out in a disastrous flood that extended as far as the city of Geneva. Some claimed that the waters actually overtopped the walls of Geneva. The backed-up flood eventually burst through the landslide dam and washed everything away downstream.

Thirty monks arrived at the landslide and began to dig into it in search of salvage. They found some bronze and iron items, but as they dug, they heard once more the subterranean bellowing. With a folly that seems incredible, but was to be repeated many times throughout history, the monks ignored the warning. The inevitable happened. A part of the hillside as yet unfallen collapsed. "It buried them completely and their dead bodies were never recovered."

In the same year, just before the plague appeared in Auvergne, there was an outbreak of prodigies in France. On several occasions, "three or four great shining lights" appeared round the Sun, "and these the country people also called suns." The observers of China would have called them shu jih (multiple suns), and considered that they portended great battles. In 6th-century Gaul, battles and civil war were endemic. The people, oppressed by warlords who recognised only the rights of conquest, "were ever on the alert for supernatural manifestations, or for what they believed to be such", and Gregory was also always ready to see omens and portents. Although he feared all natural phenomena, his descriptions of them are not, as far as we can tell, exaggerated. It is nearly always possible to identify the phenomenon he describes.

However, on the night of November 11, A.D. 577, he saw something strange. The Moon was full, and surrounded by a halo, "which is usually a sign of rain". A bright star was seen shining "in the very centre of the Moon, and other stars appeared close to the Moon, above it and below." Gregory says, "I have no idea what all this meant". Nor do we. Was the 'star' actually on the Moon? The planet Jupiter was about 5 degrees away, but this is, in terms of the Moon's apparent size, hardly close, let alone 'on'. There are a few other records of naked-eye 'stars' on the dark part of the Moon, but this appears to be the only one where such a 'star' appeared on an illuminated Moon. Did a meteor crash on to the lunar surface? Was it some optical phenomenon connected with the halo? There are a few records of lunar halo phenomena where a cross appeared on the face of the Moon.

In A.D. 578 he was in Paris when "portents appeared in the sky". Twenty rays of light shone in the north, moving from east to west. One ray was longer than the others and reached high into the sky. Pliny, after studying the records of past ages, would have classified these northern lights as 'beams' or dokoi, and said that they occurred at fixed dates owing to natural forces. Seneca, while admitting that they caused terror, would have attempted to explain them in natural terms. Now there were few records to demonstrate that such things had been seen before, and so the portents became more fearful.


Great floods swept France in A.D. 580. After twelve days of rain the rivers Loire and Allier and the mountain streams rose higher than was ever known before. The Rhône, where it meets the Saône, rose and undermined part of the city walls of Lyons. A.D. 580 was another year of terrifying phenomena. In Touraine, just before dawn, a bolis appeared. A bright light crossed the sky and disappeared into the east. Then came the explosion. "A sound as of trees crashing to the ground was heard throughout the whole region, but it can hardly have been a tree for it was audible over fifty miles or more." An earthquake shook southern France and Spain. The walls of Bordeaux tottered, and frightened citizens fled to nearby townships. Boulders dislodged from the summits of the Pyrenees crushed in their fall people and cattle. A mysterious fire, which may or may not have been connected with the earthquake, broke out. Bordeaux and surrounding villages were burned "by a fire sent from heaven…there was no other apparent cause of this fire, and it must have come from God." The city of Orleans burned also, and even wealthy inhabitants lost everything, while homes and threshing-floors "with the grain still spread out on them" were reduced to ashes.

Attempts have been made to link the meteor in Touraine with the earthquake and the "fire sent from heaven". A large enough meteor exploding in the atmosphere could ignite fires and cause an earth shock, and the conflagration at Orleans might have been caused thus. Gregory says that the earthquake at Bordeaux was in "this same year" as the meteor, however, and the shock was too widespread and too far south to have been caused by it, and the same applies to the mysterious and widespread Bordeaux fire.

There was no respite. The city of Bourges was lashed by a hailstorm. Rumours spread that the heavens had been seen on fire. A storm from the south, which seems to have affected an area of only a mile or so, and may have been a turbo or tornado, destroyed trees and houses. Fences were carried away, and men were blown off their feet and killed.

The year A.D. 582 began with an appearance of the arch-portent, a comet. Gregory seems to have seen it himself as it shone in the western sky after sunset during January. "It shone through the darkness as if it were at the bottom of a hole, gleaming so bright and spreading wide its tail. From it there issued an enormous beam of light…" Over the city of Soissons on Easter Sunday, April 19, there were chasmata. Two centres of fiery light in the sky joined together after about an hour "to become one single enormous beacon". Then they disappeared. In Paris 'real blood' fell from a cloud and stained the clothes of terrified people, who stripped them off in horror. This fall of probably dust-contaminated rain was not the most frightening portent involving 'blood'. In Tours, blood flowed from broken bread, and a man of Senlis woke one morning to find the whole interior of his house blood-spattered. Another 'great light' was seen moving across the sky, and another mysterious fire, which burned down the city of Bazas, followed.

An aerial apparition opened A.D. 583. On the wet overcast morning of January 31 at Tours, as people were on their way to church, a great ball of fire emerged from a cloud in the overcast sky. A light like that of high noon illuminated upturned faces, until the thing moved behind another cloud and darkness fell again. Gregory states that "the sky was overcast and it was raining", so this prodigy, whatever it was, cannot have been a meteor. It must have been one of the earliest records of ball lightning - a phenomenon as mysterious now as it was then.

Ball lightning, unlike many mysteries, has an ancient pedigree. In 74 B.C., the armies of Mithridates and the Romans were squaring up for a battle in Phrygia when “the sky opened”. A large luminous body, the colour of melted silver, fell between the two armies, who both “withdrew in alarm”. “A large meteor may have fallen”, one modern historian remarks dismissively, but, whatever this object was, it was no meteor. A large meteor still luminous so near the ground would still be falling at cosmic velocity, and the two armies would have been replaced by a crater. What the object might have been must remain a mystery, but 'ball lightning' is at least an inadequate label.


In A.D. 584, the northern sky at midnight was illuminated so brightly that "you might have thought day was about to dawn." A multitude of rays moved to and fro before all vanished. One day, a great circle of many colours "like what one sees in a rainbow" appeared round the Sun. A swarm of locusts 50 miles long and 100 miles broad ravaged Spain, and epidemics killed livestock. Frost seared the vineyards of Gaul, and what remained was destroyed by a terrible storm. The harassed peasants had had enough. They cried, "We don't care if these vines never bear shoots again till the end of time!", opened the gates and drove in cattle and horses. Their protests went unheeded, or as Gregory says, "called down ruination" upon them.

Sky terrors continued into December. Another brilliant bolis illuminated the countryside before dawn. Rays of light rose in the night sky, "and in the north a column of fire was seen to hang from on high for the space of two hours, with an immense star perched on top of it."

The rash of portents continued into A.D. 585. Rays of light were seen in the northern sky. Gregory says, almost with a sigh, "although, indeed, this happens often." As if in annoyance at this dismissive attitude, the northern lights put on an outstanding display for him. In October, while he was staying at Carignan in the Ardennes, the rays appeared once more in the north, this time "shining so brightly that I had never seen anything like them before". Blood-red clouds encroached on the rays from east and west. This continued for two nights; then, on the third night rays rose from all round the horizon until they filled the sky. As Gregory watched in mingled wonder and fear, a luminous cloud appeared in the zenith, and the rays rose to meet it, until he seemed to be standing beneath a multicoloured pavilion of light. Between the rays, other luminous clouds glimmered and flashed, "as if they were being struck by lightning."

But the glories of the sky were only a source of fear. Gregory wondered what disaster this spectacle foretold. Soon, a story went about concerning two "islands in the sea", which had been overwhelmed by "fire which fell from the sky" and had burned for seven days. Those of the inhabitants who were not burned alive threw themselves into the sea and were drowned. Then the sea covered the ash that remained. Many people said that the nocturnal sky lights "were really the reflection of this conflagration."

A.D. 587 was another disastrous year in France. Heavy rains in spring were followed by an unseasonable snowfall and a bitter frost after the trees were in leaf. Fruit and vines were destroyed, and returning swallows died of cold. The northern sky flashed its lights. A strange rumour spread about vessels inscribed with unknown characters that could not be erased which appeared mysteriously in peoples' houses.

An even stranger story concerned the snakes in the sky. Some people claimed to have seen 'snakes' drop from the clouds. Others said that a whole village, with its houses and their occupants, had been destroyed and swept away. No claim was made that the 'snakes' did this, but it seems likely. A reading of Pliny might have suggested that the 'snakes' were something the Romans called turbo and the Greeks called a 'typhoon' or 'whirling cloudburst', which snatched up objects and carried them with it into the sky. The clouds with the whirlwind, Pliny said, were shaped like columns and pipes or 'wild monsters'.

In November of A.D. 589, Gregory reported, the River Tiber flooded Rome so disastrously that the Papal granaries were destroyed and a number of ancient churches collapsed. A great number of water-snakes were seen in the river, surrounding "a tremendous dragon as big as a tree-trunk". One might consider these to have been waterspouts, were it not for the fact that they were all swept out to sea, drowned, and their bodies cast ashore. Their decaying remains were blamed for another outbreak of the plague.

In A.D. 590, a wide area of country was illuminated by a light as bright as noonday. Was this the aurora, or a meteor? The latter seems likely, for on a number of other occasions in this year, fiery globes were seen crossing the night sky and illuminating the earth. Bolides seem to have been frequent during this period, beginning (perhaps) with the light on the Moon in A.D. 577.

Gregory ends with a story about an earthquake. A charitable citizen of Antioch, searching for a needy inhabitant with whom he might share his evening meal, came across three mysterious white-robed strangers outside the city walls. The oldest of them waved a cloth, and half of Antioch crumbled into ruin. The stranger was about to destroy the remaining half of the city when his two companions stayed him. One picked up the swooning citizen, telling him that his wife and sons were unharmed, having been saved by “your habit of praying regularly and by your daily acts of charity”. Then the three strangers vanished. The citizen returned home, and found his family safe as promised, although their neighbours had been crushed to death beneath their collapsing houses.

Whether Gregory intended this account to be a report or a parable is unclear. However, Antioch had been ravaged by earthquakes in 526, 528 and 589.