To the north east of the Roman Empire barbarians pressed against its borders, but were held at bay everywhere except Dacia (present-day Romania). This province north of the Danube was the last won by Rome and first lost. Dacia was relinquished to the Goths and their allies in about 271 AD. The Goths were just one of the Germanic, Slavic and other peoples looking for room to spread themselves in Late Antiquity. As the Roman Empire gradually crumbled in the West from 376 AD, they burst across its former borders. When the complex criss-crossing of their movements consolidated around 700 AD, a new Europe had emerged. While some parts of it had changed relatively little from Roman times and their peoples still spoke a language derived from Latin, other regions had been radically altered. The balance of power had shifted. The empires of the first millennium BC all sprang from the advanced cultures of the Mediterranean. By the end of the first millennium AD, Europe was a patchwork of Christian states. This era of change is known as the Migration Period or Völkerwanderung (wandering of the peoples).
Who were these wandering peoples? Civilization is defined by, among other things, its literacy. The barbarians were illiterate. This means that they left us no descriptions of themselves, no histories, no bureaucratic records. To learn about them, we are dependent on archaeology and the writings of the civilized. Archaeology before the era of isotope studies was not able to detect migration with certainty. Objects may move through trade. Peoples may adopt new fashions from their neighbours. We expect people moving as a family or tribe to take with them the burial rites familiar to them. So new burial practices appearing provide the most dependable clue to new arrivals. Yet burial practices can change as people convert to a new religion.
The evidence from Classical sources is no easier to fathom. The earliest authors knew little of the homelands of the barbarians. While the Mediterranean fringe of Europe was
dotted with cities founded by the Ancient Greeks, few Greeks penetrated lands to their north.
no reliable information to pass on about the western margins of Europe, wrote Herodotus honestly in 440 BC,
Despite my efforts, I have been unable to find anyone who has
personally see a sea on the other side of Europe.1Herodotus, The Histories, trans. Robin Waterfield (1998), book 3, section 115.
No wonder then that aspects of this turmoil have been hotly debated. Most drastically, the idea of past migration was so unpopular after the Second World War that it became commonplace among academics to minimise the central feature of this period. Where there was incontrovertible documentary evidence of movement, archaeological fashion favoured a vision of small elites only moving. Some of the mobility of this period did indeed merely replace one elite with another. A good example would be the Visigoths in Spain, who were vastly outnumbered by their subjects and had no impact on the latter's language or culture. Yet distaste for mass movement imposed an intellectual cage. In this new century academics have been bursting the bars.2P. Heather, Empires and Barbarians: Migration, development and the birth of Europe (2009), chapter 1.
What were the engines of change? The population of Europe as a whole c. 200 AD is estimated at 36 million, 28 million of them within the Roman Empire.3C. McEvedy and R. Jones, Atlas of World Population History (1978). No such figures can be accurate, but undoubtedly the bulk of Europe lay within the Empire. Why and how did those outside the Empire contrive to break into a populous zone guarded by the Roman Legions?
After centuries of expansion, Rome had locked within its borders the most productive part of Europe. That was deliberate. Romans were interested in good agricultural land, mineral resources and trading opportunities. Their first target, after expanding to the whole of Italy, was the rest of Mediterranean Europe, which had the highest levels of agricultural productivity in Europe and a sophisticated material culture. Julius Caesar and his great-great grandnephew added the richest of the Celtic-speaking lands. Although there were attempts to conquer the Germani for the glory of it, Romans surely knew that the Germanic economy was too poor at the time to repay the effort of conquest in either in booty or taxes.4P. Heather, Empires and Barbarians (2009), pp. 4-5. They settled for the Rhine as their border. By so doing the Romans established a firm frontier between the haves and have-nots. The normal human urge to seek better fortune elsewhere, if times are hard at home, was thwarted. Waves of have-nots threw themselves against the barriers, or sought a way to gain a share of Imperial wealth by trade or alliance.
The Germani had been expanding out of Jutland for centuries before the Romans halted them at the Rhine.
The pressures behind their onward march included climate shift and environmental crises. Yet the Empire itself shuddered under natural disasters, which played their part in
weakening its economy, reducing its population levels, and creating the opportunity for
barbarians to advance. The difficulty of manning so lengthy a border, and fighting
off attacks on several fronts was another factor in the Imperial collapse, along with periodic civil war.5R.P. Duncan-Jones,Economic change and the
transition to Late Antiquity, chapter 2 in S. Swain and M. Edwards, Approaching Late Antiquity: the transformation from early to late empire (2004).
The Slavs began their migrations after the fall of the Western Roman Empire. They were partly drawn by
opportunities elsewhere, and partly driven by invaders from the steppe. Good land to their west had been almost denuded of population by strife, plague and the migration of other
peoples, while to their east the sparsely-populated forest zone offered new trapping and trading opportunities with the founding of Kievan Rus.6P.
Heather, Empires and Barbarians (2009), pp. 439-45.
It has long been argued that the chief trigger of the Migration Period was pressure from Asia. Most obviously attacks from the steppes pushed successive waves of Germani and Slavs across the border into the Roman Empire. This was just one chapter in a long story of instability in Eastern Europe due to nomadic incursions. As one culture was laid waste, another could move into its former land.
The Danube provided the route into Central Europe from the steppe. It was followed by Indo-Europeans in the Copper Age. Then the Cimmerians, descendants of those Indo-Europeans who had remained on the steppe, swept into the Carpathian Basin in the 9th and 8th centuries BC. The Cimmerians were fleeing before their distant relatives, the fierce, nomadic Scythians. The Scythians were descendants of Iranian-speakers who had moved deep into Asia long before, but were driven westwards by the rise of Turkic tribes. Around 500 BC the Scythians too established enclaves in the Carpathian Basin, from which they raided the Lusatian Culture, the variety of Urnfield Culture which extended over what is now Poland and parts of neighbouring countries. Lusatian strongholds were burned to the ground.7P. Urbanczyk, Iron Age Poland, in P. Bogucki and P.J. Crabtree (eds.), Ancient Europe 8000 BC–AD 1000: Encyclopaedia of the Barbarian World, vol. 2 (2004), pp. 414-6; B. Cunliffe, Europe Between the Oceans (2008), fig 9.1. The collapse of the Lusatian Culture opened the way for the further expansion of Germani into Lusatian territory, which had begun in the north some two centuries earlier. For the Goths and Vandals the route westwards was blocked by other expanding Germanic tribes, while the forest zone to the east was less appealing to farmers. Gradually they moved southwards to the Black Sea. The Huns drove the Goths across the Roman border. Nomads sweeping in across the steppe, the Huns displaced the Goths from their Black Sea homeland in 375. The collapse of the Hunnic Empire after 454 AD left a power vacuum on the western steppe which some groups of Slavs exploited. It seems that the main draw was the wealth of Byzantium. From the steppe one could trade across the Black Sea. The more warlike served as soldiers in Roman employ, or raided across the border into the Balkans.8P. Heather, Empires and Barbarians (2009), p. 439.
The pattern was repeated as the Avars swept in from the steppe in mid-sixth century AD, treating conquered peoples like chattels. The desire to escape the Avars explains not only the Slavic push across the Byzantine frontier into the Balkans, but their spread from Bohemia towards the Saale and Elbe after the mid 6th century and northwards into what is now Poland.9P. Heather, Empires and Barbarians (2009), pp.443-5. The latter region had become progressively depopulated in the previous two centuries. Within what is now Poland only Pomerania in the north remained well-populated. The losses can be explained by the invasion of the Huns and movement south of the Goths and Vandals. The settlement void was filled by the Slavs.10A. Buko, The Archaeology of Early Medieval Poland: Discoveries - hypotheses - interpretations (2008), pp. 61-2, 86; P. M. Barford, The Early Slavs; Culture and Society in Early Medieval Eastern Europe (2001).
Yet nomadic movements are only part of the picture. The workings of nature played as great a part in shifting the balance of power from south to north, and from Empire to a patchwork of kingdoms.
The Teutones and Cimbri who swooped on Rome in 113 BC were driven by the flooding of their own lands to look for a new homeland. They travelled with their women and children.11Lucius Annaeus Florus, The Epitome of Roman History, book 1, chapter 38; Plutarch, The Lives, The Life of Marius, 11. It was an act of desperation, driven by a catastrophe that was far from unique. Britain was once joined to the Continent by Doggerland, which was submerged by the rising sea levels as glaciers melted in the Holocene. One dramatic event speeded up the process - a tsunami around 6200 BC.12B.Weninger et al., The catastrophic final flooding of Doggerland by the Storegga Slide tsunami, Documenta Praehistorica, vol. 35 (2008), pp. 1-24. Since then the North Sea coast of what is now the Netherlands and Germany has been gradually subsiding.13A. Vink et al., Holocene relative sea-level change, isostatic subsidence and the radial viscosity structure of the mantle of northwest Europe (Belgium, the Netherlands, Germany, southern North Sea), Quaternary Science Reviews, vol. 26, nos. 25-28 (December 2007), pp. 3249-3275. Much of the Netherlands is now below sea level and has been reclaimed from the sea since around 1000 AD. The map left shows the area that would be underwater now, were it not for flood protection. The key feature is the broken strip of higher ground jutting out of the sea. It forms a natural protective barrier, within which is an alluvial plain. As the rise in sea level decelerated after 4000 BC, the plain silted up. By around 1000 BC, it was a district of fresh-water peat swamps punctuated by rivers and a large lake, with salt marshes to the north.14D.J.Beets and A.J.F. van der Spek, The Holocene evolution of the barrier and the back-barrier basins of Belgium and the Netherlands as a function of late Weichselian morphology, relative sea-level rise and sediment supply, Netherlands Journal of Geosciences = Geologie en Mijnbouw, vol. 27 (2000), pp. 3-16.
Today the remnant of that natural embankment is the Frisian Islands, off the shore of northern Nethlands and Germany. Then there is a break before the Wadden Sea Islands
along the coast of Denmark. Between these island chains and the coast lies an intertidal zone called the Wadden Sea, a shallow body of water with tidal clay flats and wetlands.
Some intrepid souls settled there in the Iron Age. Their settlement sites began to rise partly by natural
accumulation of debris, and partly by deliberate dumping of clay and turf, to form artificial mounds, known as terps (terpen in Dutch, wurten in German). These
provided some degree of safety from flooding. Thousands of terps are spread along the coastal districts of the Netherlands, Germany and southern Denmark. The earliest date to
around 600 BC, but terp-building expanded greatly from c. 200 BC.15M. Todd, The Early Germans, 2nd edn. (2004), pp. 63-64.
Pliny the Elder was the first to leave us a description of the Wadden Sea:
a vast tract of land, invaded twice each day and night by the overflowing waves of the ocean in
the territory of the Chauci. He witnessed the way of life of those
inhabiting either the more elevated spots of land, or else eminences artificially constructed, and of a height
to which they know by experience that the highest tides will never reach.16Pliny the Elder, The Natural History, trans. J. Bostock and
H.T. Riley (1855), book. 16, chapter 1.
He spoke too soon. The subsidence continued. Flooding of the Belgian coastal plain and the Zeeland area started shortly after 200 AD and transformed the peatlands into wide estuaries, mud flats and salt marshes. A large area of the northern Netherlands was flooded and the Wadden Sea became connected to the large lake in the centre of the country.17D.J.Beets and A.J.F. van der Spek, The Holocene evolution of the barrier and the back-barrier basins of Belgium and the Netherlands as afunction of late Weichselian morphology, relative sea-level rise and sedimentsupply, Netherlands Journal of Geosciences = Geologie en Mijnbouw,vol. 27 (2000), pp. 3-16. This rise in sea level was so dramatic that many terps were deserted. Thousands of people would have been looking for new homes.
Switches of climate from around 250-550 AD coincided with the demise of the Western Roman Empire and the turmoil of the Migration Period. Tree-felling dates mirror the rise and fall of the Empire in the west. The rise in tree-felling from 300 BC to 200 AD tells a tale of building boom and deforestation for farming, which reached a peak around 250 AD. From then on tree harvesting was in decline. During the 3rd century a drying climate was the problem. Parched land would mean dying crops, particularly in the south. Then rainfall increased during the 300s, while temperatures fell. It turned even wetter in the 5th century as the Western Empire tottered and fell. Then rainfall fell sharply in the first half of the 6th century just as other disasters struck. In 536 a volcanic eruption threw enough dust into the atmosphere to cool the northern hemisphere for over a decade.18U. Büntgen et al., 2500 Years of European Climate Variability and Human Susceptibility, Science, vol. 331, no. 6017 (4 February 2011), pp. 578-582; R. Dull, Did the TBJ Ilopango eruption cause the AD 536 event?, American Geophysical Union, Fall Meeting 2010: abstract http://adsabs.harvard.edu/abs/2010AGUFM.V13C2370D.
Crop failures would have led to food shortages, weakening resistance to disease. Plagues are recorded at intervals between 251 and 270. In regions where there have been systematic archaeological surveys - France, Italy and the Rhineland - they reveal a drastic fall in the number of occupied rural sites in the 3rd century, suggesting a shrinking population. In Iberia there was a dramatic fall in mining. By contrast Rome's African provinces were thriving. Egypt became the bread-basket of Rome, while Tunisia supplied its pottery. There is scattered evidence that the population was actually rising in some of Rome's eastern provinces - Greece and Syria.19R.P. Duncan-Jones, Economic change and the transition to Late Antiquity, chapter 2 in S. Swain and M. Edwards, Approaching Late Antiquity: the transformation from early to late empire (2004). Was this a factor in Diocletian's decision to rule the Roman Empire from Nicomedia in Anatolia? He divided the empire into east and west, putting a lieutenant in charge of the west. It was the start of a process that culminated with the loss of the Western Empire to the Germani. Constantine the Great continued Diocletian's eastern leaning, making Constantinople (Byzantium) the capital of the Roman Empire in 330. It has been argued that the increasing population of Asia Minor and the Balkans in 395-476 helped save the eastern half of the empire as the west crumbled. In the Balkans the city of Stobi was prosperous and growing, while the province of Istria was exporting grain to Ravenna.20J. C. Russell, That Earlier Plague, Demography, vol. 5, No. 1 (1968), pp. 174-184.
Then came the Plague of Justinian. The first pandemic recorded in the Western world broke out in Egypt in 541 and reached Jerusalem in the same year. All trade routes led to Constantinople. The disease reached the heart of the Byzantine Empire the following spring, with devastating ferocity.21D. Stathakopoulos, Crime and punishment: the plague in the Byzantine Empire, chapter 5 in L.K. Little (ed.), Plague and the End of Antiquity: The Pandemic of 541-750 (2008).
Now the disease in Byzantium ran a course of four months, and its greatest virulence lasted about three. And at first the deaths were a little more than the normal, then the mortality rose still higher, and afterwards the tale of dead reached five thousand each day, and again it even came to ten thousand and still more than that... many houses became completely destitute of human inhabitants.22Procopius, The History of the Wars, vol. II, chapter 23.
Sweeping on from Constantinople, the plague wiped out entire urban populations. It sped around the Mediterranean to Illyria, Greece, Italy, Gaul, Iberia and North Africa. It even reached the British Isles. It remain virulent in all these lands for just over two centuries, coming and going in an unpredictable and terrifying way.23L.K. Little, Life and afterlife of the first plague pandemic, chapter 1 in L.K. Little (ed.), Plague and the End of Antiquity: The Pandemic of 541-750 (2008). Plague probably killed about half the population of Constantinople and a third of that of Europe in its first wave, while later waves killed so many more that the Byzantine Empire had lost half its population to plague by 700 AD.24J.C. Caldwell, Demographic Transition Theory (2006), p. 390. The initial and gravest blow to the empire came just as Justinian was intent restoring it to its former extent. He had recovered Italy from the Ostrogoths and Africa from the Vandals. His advances slowed after the plague. The Empire was too weakened by natural disasters and fighting on other fronts to achieve his dream. So the barbarian hold on the west was consolidated.
Those towns and kingdoms trading with the empire were doubtless worse affected by plague than more isolated
barbarians initially. In Britain the Anglo-Saxons pressed
westwards once more in the 550s after a long lull in their advance.25Anglo-Saxon Chronicle. Were they taking advantage of
losses among the post-Roman British? Certainly the plague caused a
great mortality in Ireland in 544. In the long term the Anglo-Saxons themselves were not immune. Bede
recorded the pestilence that attacked Britain in 664
raging far and wide with cruel devastation.26J. Maddicott, Plague in seventh-century England,
chapter 9 in L.K. Little (ed.), Plague and the End of Antiquity: The Pandemic of 541-750 (2008); Bede, The Ecclesiastical History of The English People,
Plague mortality within Illyria from 542 may partly explain the comparative ease with which Slavs came to overwhelm Illyrians by the mid-7th century.27A. Soltysiak, The plague pandemic and Slavic expansion in the 6th-8th centuries, Archaeologia Polonia, vol. 44 (2006), pp. 339-364. Although the distraction of the Byzantine Empire by war with Persia was the key military factor, the Slavs were not simply a governing elite in the Balkans. Slavic languages are spoken today over much of the former Roman province of Illyricum. That suggests that the incomers were not hugely outnumbered by the locals.
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