The Migration Period (between 375 AD to 568 AD) was the controversial time that according to historians brought the fall of The Roman Empirenote and triggered what is called Dark Age Europe. In history the period is also called Late Antiquity, as it saw the transition from Ancient Rome to The Low Middle Ages.
During this time, there were massive invasions of peoples into Western and Southern Europe, at the time provinces of the Empire. These people were mainly all the Germanic tribes (but there were others like the iranian Avars and the Huns who's ancestry and language are unknown to us) that lived beyond the ‘’limes’’, the border represented by the Rhine and Danube between what was Rome and what was ‘’Barbaricum’’ (Germanic tribes never subjugated by Romans). This period curiously changes name in a Perspective Flip between Romance languages and Germanic languages: in Germanic languages is ‘’Migration Period” Völkerwanderung, in Romance languages and Greek, is called the “Barbarian Invasions” (after all, the formers’ ancestors were migrating to better lands, the latters’ ancestors were flooded by Germanic tribes never heard about in a matter of few decades).
Historians give differing dates regarding its length, but the Migration Period is typically regarded as beginning with the invasion of Europe by the Huns from Asia in 375 and ending either with the conquest of Italy by the Lombards in 568, or at some point between 700 and 800 (when the Slavs were settling in Southern, Central and Eastern Europe and the Vikings finally showed up). Historians use a more neutral term of "Late Antiquity". It overlaps quite a bit with Dark Age Europe. It did not happen abruptly when some German tribe chiefs decided that moving across the border was one bad idea. There are several causes for the migration, with climate change and population crisis being the chief factors for the decline. There is even a theory that sees the construction of the Great Wall of China to keep the Nomadic steppe tribes at bay causing a "domino effect" of the Huns turning westward, leading to the Huns falling upon the Goths and other Germanic tribes who sought to seek refuge inside Roman territories.
However, the Roman Empire was steadily declining since the 3rd century CE, with plagues, economic depression, and population decline forced the authorities to rely more and more on Barbarians, because thanks to the Antonine Plague population growth fell and most of all, there was a decline of new joiners in the army. Enlisting in the army was instead the faster way for outsider to integrate in the empire and acquire citizenship. That is why between the 3rd and 4th century the Roman army would see a huge shift in its ethnic composition (high-ranking generals were prominently of Germanic origins) and fighting style, as the Germanics would not get accustomed to Roman style of fighting and they would rather use their own weapons. This is the period when axes and slashing swords became popular (Roman legions previous used stabbing swords, the gladius).
The downside of this arrangement was that instability in the army was common. A Culture Clash between the Germanic and Roman concept of communitynote : the Romans were first of all citizens of a centralized State, the Germanic tribes were strongly individualistic, and would call an assembly to discuss public matters (the thing) only in extraordinary circumstances. So, while the Romans tended to be loyal to an institution, Germanics were mainly loyal to a leader elected by them. Also their fighting style mirrored perfectly the Soldier vs. Warrior scheme: the Romans had a professional army with codified tactics and organization and they would fight for the pretty mundane reason that they were paid to do so, while the Germanics believed that War Is Glorious and their war prowess would earn eternal glory (see Norse Mythology, which applies as well to other Germanic people), so they relied more on brute force than tactics. Because of huge cultural differences, Romans would look down on soldiers and generals of Germanic ethnicity (curiously, said generals were kings of their tribe, but to the Romans said titles meant nothing, and couldn't tell apart one tribe from another), seeing them as treacherous, despite the fact that some of these Germanics would defend Romans with their lives and most of the high-ranking officers were integrated in the society and married Roman women. A breaking point was then inevitable.
However, the great migration were definitely caused by a snowball of peoples migrating from northeast, since overpopulation and climatic change would drive them to seek new lands southwards. Incursions of Germanic tribes already occurred in the 3rd century with the Goths raiding the Balkans, but the first crisis occurred in the 376 CE when the Huns pushed the Tervingi, a Gothic tribe, towards the limes on the Danube river, asking the Romans permission to cross it. The emperor Valens granted the permission, since he needed men for his campaign against Sassanid Persia. It seemed that the crossing would go smoothly, but truth was that some of the Roman officers profited too much from the refugees situation, selling them food at sky-high prices, confiscating weapons, and selling their women and children to slavery. Inevitably the tribes would turn against them, taking the ‘’other’’ weapons that they hid all too well from the officers, and they crushed the Roman army at the Battle of Marcianople. Emperor Valens was forced to deal with them and thought the he would easily crush the revolt, even asking his nephew and co-emperor in the West Gratian to send an army for help. They would face each other at the Battle of Adrianople in 378, where the Gothic cavalry would utterly crush the Eastern Roman Army and Valens himself would lose his life.
This was the beginning of the end. The Tervingi would in a few decades collapsed into the Visigoths, the one that would again rebel against the Roman emperor (the Western, this time) and sacked Rome in 410 under their king Alaric, before founding the Visigothic Kingdom in the territories of Aquitania, Provence and Iberia, and ruling for 250 years. Other tribes that broke into the Western Empire were a confederation of Herulian, Rugian, and Scirian warriors, whose king Odoacer (himself a former general in the Western army) deposed boy emperor Romulus Augustulus in 476. They would be later supplanted by the Ostrogoths, led by Theodoric the Great, who settled in Italy. In Gaul, the Franks (a confederation of western Germanic tribes that were servicing in the army since the 3rd century) broke into Roman lands gradually at the beginning of 5th century, crossed the frozen Rhine and seized northern Gaul and Belgium. The Franks established a kingdom there, and the Western emperor was forced to accept them, as retaking Northern Gaul would employ too much men and money that they did not have. This is also the reason why during the 3rd century Roman legions would leave Britain to fend for itself, and after the recurring raids of the Celtic tribes from beyond the Hadrian Wall, the Anglo-Saxons would settle in Britain during the 5th century. The Burgundians instead settled in Northwestern Italy, Switzerland and Eastern France in the 5th century, before being driven off by the new Frankish kingdom.
Let's now take a look to the main tribes' shenanigans.
One of the main tribes of the Goths (there were also the Ostrogoths, the Gepids, the Tervingi and so on). The Goths originally hailed from Scandinavia from where they migrated by sea under their king Berig. Similarities between the Goths and that of the Gutes and Geats (tribes that stayed in Scandinavia), and recordings of emigration from the medieval Gutasaga, lead to evidences of their origin in Gotland, modern-day Sweden. The distinction between Visigoths and Ostrogoths was invented by historian Jordane centuries after, so odds are that they called themselves Goths without the distinctions that Romans applied to them.
The Visisgoths among them already appeared in Eastern Europe during the 3rd century, with costant raiding in the territories of Thracia, Dacia, and Northern Greece. By the reign of Constantine, the Goths were living more or less peacefully outside the Danube. Tragedy befall when in 376 CE one of their leaders, Fritigern, requested to the Eastern emperor Valens to be allowed to settle with his people on the south bank of the Danube, hoping to escape from the Huns. Such arrangement went horribly wrong and the Goths turned against the Romans, ensuing the Gothic War and the already mentioned Shocking Defeat Legacy of Adrianople.
One of the last competent Roman emperors, Theodosius I, negotiated a treaty with the remaining Gothic forces, allowing some contingents of Barbarians to settle in Thrace south of the Danube frontier, and fight for the Romans as foederatinote . Peace would last until Theodosius' death in 395, when tensions would rise again under the Visigothic king Alaric I.
Alaric was in his military career constantly screwed over by the Emperor and his lieutenants, as he fought numerous battles for the Romans losing more than what he gained. In 394, he helped Theodosius defeat the Frankish usurper Arbogast at the Battle of Frigidus, sacrificing around 10,000 of his men (Theodosius, always the pragmatist, used Gothic forces to do a Zerg Rush against enemy lines, keeping the others as reserves) and Alaric received little recognition from the emperor, who at the time favored his sorta-of son-in-law (the husband of his favorite niece) Stilicho, himself a Romanised Vandal. Pissed off by the perceived ungratefulness (he expected at least a promotion to magisterium like Stilicho) Alaric mutinied at the right time, when Theodosius was dying and dividing the empire between his very incompetent sons: Honorius in the West, Arcadius in the East.
The Visigoths under Alaric would wander around Europe for a good fifteen years between 396 and 412. Alaric was trying to force the hand of an Emperor (Eastern or Western, who cared) to name him magister militium, by blackmailing him with his huge Gothic horde. His rival Stilicho met him once in a while on battlefield to settle the matter, but inexplicably Alaric would escape from Stilicho's clutches. The theory is that Stilicho was constantly postponing the moment he would deal seriously with Alaric because he feared the emperor would dismiss him once he turned that noise off.
Unexpectedly, Alaric invaded Italy in 401. Stilicho met him in the open field, managed to win twice and allowed Alaric to withdraw from Italy a second time.Between 406 and into 407, another federation of barbarians (Vandals, Sueves and Alans,) crossed the Rhine into Gaul, while at the same time a common soldier in Britain named Constantine crowned himself emperor and his rebellion spread to Gaul. Stilicho had to personally deal with more enemies at once and Alaric exploited the occasion to march again on Italy, demanding 4,000 pounds of gold for keeping his armies quiet. Stilicho and the Western Emperor Honorius (who was his son-in-law by the way) begrudgingly agreed to pay. The Vandal general now came under suspicion because he let Alaric escape twice and would seek a negotiation instead of destroying him.
In 408 Honorius decided the he would like his father-in-law better if he was buried under his feet and ordered the execution of Stilicho on the basis that Stilicho had tried to make a treacherous deal with Alaric. The result was not only losing a highly competent general, but thousands of Stilicho’s barbarian auxiliaries (loyal only to Stilicho, mind you) joined Alaric. Honorius had made Rome more vulnerable than ever, since there was no general with Stilicho’s competence that would defend Italy’s borders.
In 408, Alaric was refused again the sum demanded from Honorius and he led his force of around 30,000 men on a march toward Rome, putting the city a strict blockade. Taking the citizens by famine, Alaric would collect a ransom of 5,000 pounds of gold, 30,000 pounds of silver, and 40,000 freed Gothic slaves that joined his army. Thus ended Alaric's first siege of Rome. The second siege would occur when Alaric's expectation of being named head of the Roman Army was not met. When Honorius refused, Alaric proceeded to besiege Rome again in late 409, and also to proclaim a senator, Priscus Attalus (someone that would meet his requests), as a rival emperor. The Sack of Rome lasted for three days. The violence of the sacking is disputed among historians, with some accounts speaking of heavy Rape, Pillage, and Burn, while others dismissed such grim records on the basis that Alaric would respect the churches and the violence was contained. In spite of that, Alaric would collect a booty of legendary proportions and most of all a ridiculously important hostage for negotiations... Honorius' younger sister Galla Placidia. Legend has it that when he heard about the sack, Honorius was horrified... because he thought his pet chicken Rome was dead. When he was told that it was the city of Rome that was destroyed, not the chicken, Honorious breathed a sigh of relief. While the story may not be true, it reflects how poorly Honorious was seen by many Romans.
The poor lass had a life worthy of Daenerys Targaryen and Cersei Lannister. Her brother Honorius had married twice (to Stilicho's daughters) but would not get any children from these marriages. So anyone who would marry his sister would automatically get his ticket to be next in line to the emperor. Marrying Placidia off to someone of his choosing was the perfect negotiation leverage for Alaric, who presented his brother-in-law Athaulf as his candidate. Honorius flat out refused such arrangements, as he already had his candidate in the (barely Roman) general Costantius. Placidia spent the next two years wandering with the Visigoths in Campania, Lucania and Calabria in waiting for an arrangement with Honorius for a land where the Visigoths would settle. Always the Born Unlucky, Alaric would die of malaria during their hopeless wandering, and legend says he's buried in the bed of the river Busento with a huge treasure. Those Wacky Nazis tried to find said treasure to no avail.
The next king elected was the already mentioned Athaulf, Galla Placidia's suitor, who renewed his marriage proposal now with better relations with the Roman court. Athaulf led his tribes across Italy and then to Southern Gaul, where he married Placidia in a lavish cerimony. The bride was gifted the gold stolen from the Sack of Rome, the marriage was celebrated with Roman rites, and poor Priscus Attalus, who failed to become emperor, found out he was better suited as a wedding planner, as he wrote the epithalamia for the newlyweds. According to historians, they were Happily married, but sadly it wouldn't last. Their only son, Theodosius (named after Placidia's father, the late emperor,) died in infancy, and shortly after Athaulf himself was murdered by a rival in Barcelona, where the Visigoths had settled at the time.
When the instability was settled among the Visigoths, it was time for Galla Placidia to go back to her brother's court in Ravenna. The new Visigoth king Wallia signed a peace treaty with the Roman envoy stipulating that Placidia be restored to her brother, six hundred thousand measures of wheat were to be delivered to the Visigoths, along with the foederati status and permission to settle in Iberia and Southern Gaul, where the Visigothic Kingdom was now founded.
Placidia would go on to marry the general Constantius and become empress, but not before taking with her a contingent of Visigoths that would be her personal guard. She has the rather singular story of being first Queen of the Goths, then Western Roman Empress.
The Visigothic Kingdom would last in France until the 6th century, when the Franks would conquer a kingdom in Gaul (that's another story), while the kingdom in Iberia would fall in the 8th century to the Moors, who would establish Moorish Spain.
The Vandals (the etymology would mean "the wandering people") first appeared in Roman records inhabiting modern-day Poland. According to legends, the Vandals migrated from southern Scandinavia to the area between the Oder and Vistula rivers during the 2nd century BC and settled in Silesia from around 120 BC. During the 1st century CE they would expand into Dacia and Pannonia during the Crisis of the Third Century, but were confined to Pannonia by the Goths around 330 AD. However Constantine the Great would allow them to settle there for the next 60 years, even enlisting in the army. The aforementioned Stilicho had a Vandal father.
All changed when the Huns appeared and pushed westwards all the other tribes into the territory of the Roman Empire and, fearing that they might be targeted next, the Vandals were also pushed westwards, crossing the Rhine into Gaul along with other tribes in 406. They would then face the resistance of the Franks, who already controlled northern Gaul. Defeated the Franks, the Vandals crossed the frozen Rhine in the winter of 406, devastating the regions westwards.
In 409 the Vandals under their king Gunderic, the Vandals headed southward through Aquitaine and then to Iberia, with their main groups, the Hasdingi and the Silingi, settling in Gallaecia (northwest Iberia) and Baetica (south-central Iberia). Fun fact: the region of "Andalusia" in Southern Spain takes its name from the Vandals. Such arrangements would not last as well. The Visigoths invaded Iberia on the orders of the Romans before and crushed the Silingi Vandals and the Alans in 418, killing the Alan king Attaces. The remainder of his people subsequently appealed to the Vandal king Gunderic to accept the Alan crown, merging the two tribes.
In 429, under their king Genseric (Gunderic's half-brother) the Vandals entered in North Africa, in modern-day Morocco and Algeria, putting under siege for more than one years St Augustine's hometown, Hippo Regius and the Saint himself would not see the end of the siege alive. Peace offers would come from Ravenna and the emperor Valentinian III. Better, from his mother Galla Placidia, the Regent for Life. Her magister militium Bonifacius signed a treaty with Genseric, where the emperor would acknowledge king of the lands conquered, but the Vandals would abstain from attacking Carthage, pay a tribute to the emperor and send Genseric's son Gunderic to Rome as hostage.Ten years late Genseric would attack Carthage anyway. By 439 they established a kingdom which included the Roman province of Africa as well as Sicily, Corsica, Sardinia, Malta and the Balearic Islands.They fended off several Roman attempts to recapture the African province, and sacked the city of Rome in 455.
This one deserves its own mention. In 455, the Roman emperor Valentinian was murdered in a conjure by the senator Petronius Maximus, allegedly because Valentinian got frisky with Petronius' wife (and many other women) and usurped the throne. Petronius had set sight on Valentinian's widow, Licinia Eudoxia, and also wanted to betroth her daughter Eudocia to his own son. Young Eudocia was actually promised to Genseric's son, Huneric (the one who was hostage in Rome). Licinia Eudoxia herself wanted to escape the Unwanted Spouse and allegedly sent a messagw to Genseric, asking to march on Italian soil. The invasion was a recipe for disaster. Pope Leo I requested Genseric to keep at bay spare the inhabitants of Rome and not destroy the city (read: do not indulge too much on Rape, Pillage, and Burn). Genseric did just that, but also robbed the city blind, and that's how the term "vandalism" was born. Licinia Eudoxia and her daughters were them smuggled to Carthage (more as guests than hostages) and Eudoxia would go on and marry Huneric as promised.
Their kingdom collapsed in the Vandalic War of 533–34, in which Emperor Justinian I's forces reconquered the province for the Eastern Roman Empire.
Just in case you were wondering why isn't France called Gaul anymore, these guys are the answer. The Franks (yet another Germanic confederation of tribes) first appeared in Roman records in the 3rd century CE. They became relevant as the Romans were losing control of the Rhine region, both as enemies and occasional allies. They appeared to have other enemy tribes, like the Saxons, and were among the firsts who saught to move into the Roman Empire.