The Migration Period was a time of widespread migrations within or into Europe in the middle of the first millennium AD. It has also been termed the Völkerwanderung (German) and, from the Roman and Southern European perspective the Barbarian Invasions. Many of the migrations were movements of Germanic, Slavic, and other peoples into the territory of the then Roman Empire, with or without accompanying invasions or war. The migrants comprised war bands or tribes of 10,000 to 20,000 people, but in the course of 100 years, they numbered not more than 750,000 in total, compared to an average 39.9 million population of the Roman Empire at that time. Although immigration was common throughout the time of the Roman Empire, the period in question was, in the 19th century, often defined as running from about the 5th to 8th centuries AD. The first migrations of peoples were made by Germanic tribes such as the Goths (the Visigoths and the Ostrogoths), the Vandals, the Anglo-Saxons, the Lombards, the Suebi, the Frisii, the Jutes, the Burgundians, the Alamanni, the Scirii and Franks; they were later pushed westwards by the Huns, the Avars, the Slavs and the Bulgars. Later invasions (the Viking, the Norman, the Hungarian, the Moorish, the Turkic, and the Mongol), also had significant effects (in North Africa, the Iberian Peninsula, Anatolia and Central and Eastern Europe); however, they are outside the scope of the Migration Period. The Barbarian Invasions may be divided into two phases. The first phase, occurring between A.D. 300 and 500, is partly documented by Greek and Latin historians but difficult to verify archaeologically. It puts Germanic peoples in control of most areas of what was then the Western Roman Empire. The Tervingi entered Roman territory (after a clash with the Huns) in 376. Some time thereafter in Marcianopolis, the escort to Fritigern (their leader) was killed while meeting with Lupicinus. The Tervingi rebelled, and the Visigoths, a group derived either from the Tervingi or from a fusion of mainly Gothic groups, eventually invaded Italy and sacked Rome in 410, before settling in Gaul, and then, 50 years later, in Iberia, founding a kingdom that lasted for 250 years. They were followed into Roman territory first by a confederation of Herulian, Rugian, and Scirian warriors, under Odoacer, that deposed Romulus Augustulus on 4 September AD 476, and later by the Ostrogoths, led by Theodoric the Great, who settled in Italy. In Gaul, the Franks (a fusion of western Germanic tribes whose leaders had been aligned with Rome since the third century A.D.) entered Roman lands gradually during the fifth century, and after consolidating power under Childeric and his son Clovis’s decisive victory over Syagrius in 486, established themselves as rulers of northern Roman Gaul. Fending off challenges from the Allemanni, Burgundians, and Visigoths, the Frankish kingdom became the nucleus of what would later become France and Germany. The initial Anglo-Saxon settlement of Britain occurred during the fifth century, when Roman control of Britain had come to an end. The Burgundians settled in North Western Italy, Switzerland and Eastern France in the fifth century. The second phase took place between 500 and 700 and saw Slavic tribes settling in central and eastern Europe (notably in eastern Magna Germania), gradually making it predominantly Slavic. Additionally, Turkic tribes such as the Avars became involved in this phase. In 567, the Avars and the Lombards destroyed much of the Gepid Kingdom. The Lombards, a Germanic people, settled in Italy with their Herulian, Suebian, Gepid, Thuringian, Bulgarian, Sarmatian and Saxon allies in the 6th century. They were later followed by the Bavarians and the Franks, who conquered and ruled most of Italy. The Bulgars, originally a nomadic group from Central Asia, had occupied the Pontic steppe north of Caucasus since the second century, but after, pushed by the Khazars, the majority of them migrated west and dominated Byzantine territories along the lower Danube in the seventh century. During the early Byzantine–Arab Wars, Arab armies attempted to invade southeast Europe via Asia Minor during the late seventh and early eighth centuries, but were defeated at the siege of Constantinople (717–718) by the joint forces of Byzantium and the Bulgars. During the Khazar–Arab Wars, the Khazars stopped the Arab expansion into Europe across the Caucasus (7th and 8th centuries). At the same time, the Moors (consisting of Africans like the Haratin Moors of the African country of Mauritania (Mooritania), Arabs and Berbers) invaded Europe via Gibraltar (conquering Hispania the Iberian Peninsula from the Visigothic Kingdom in 711), before being halted. These battles broadly demarcated the frontiers between Christendom and Islam for the next millennium. The following centuries saw the Muslims successful in conquering most of Sicily from the Christians by 902. The Hungarian conquest of the Carpathian Basin from around 895, and the Viking expansion from the late 8th century conventionally mark the last large movements of the period. Christianity gradually converted the non-Islamic newcomers and integrated them into the medieval Christian order.
The Sack of Rome occurred on August 24, 410. The city was attacked by the Visigoths led by King Alaric. At that time, Rome was no longer the capital of the Western Roman Empire, having been replaced in that position first by Mediolanum in 286 and then by Ravenna in 402. Nevertheless, the city of Rome retained a paramount position as "the eternal city" and a spiritual center of the Empire. The sack was a major shock to contemporaries, friends and foes of the Empire alike. This was the first time in almost 800 years that Rome had fallen to a foreign enemy. The previous sack of Rome had been accomplished by the Gauls under their leader Brennus in 390 or 387/6 BC. The sacking of 410 is seen as a major landmark in the fall of the Western Roman Empire. St. Jerome , living in Bethlehem at the time, wrote that "The City which had taken the whole world was itself taken." Honorius arranged for a meeting with Alaric about 12 kilometers outside of Ravenna. As Alaric waited at the meeting place, Sarus, who was a sworn enemy of Ataulf and now allied to Honorius, attacked Alaric and his men with a small Roman force. Peter Heather speculates Sarus had also lost the election for the kingship of the Goths to Alaric in the 390s. Alaric survived the attack and, outraged at this treachery and frustrated by all the past failures at accommodation, gave up on negotiating with Honorius and headed back to Rome, which he besieged for the third and final time. On August 24, 410, the Visigoths entered Rome through its Salarian Gate, according to some opened by treachery, according to others by want of food, and pillaged the city for three days. Many of the city's great buildings were ransacked, including the mausoleums of Augustus and Hadrian, in which many Roman Emperors of the past were buried; the ashes of the urns in both tombs were scattered. Any and all moveable goods were stolen all over the city. Some of the few places the Goths spared were the two major basilicas connected to Peter and Paul, though from the Lateran Palace they stole a massive, 2,025 pound silver ciborium that had been a gift from Constantine. Structural damage to buildings was largely limited to the areas near the old Senate house and the Salarian Gate, where the Gardens of Sallust were burned and never rebuilt. The Basilica Aemilia and the Basilica Julia were also burned. The city's citizens were devastated. Many Romans were taken captive, including the Emperor's sister, Galla Placidia. Some citizens would be ransomed, others would be sold into slavery, and still others would be raped and killed. Pelagius, a Roman monk from Britain, survived the siege and wrote an account of the experience in a letter to a young woman named Demetrias. "This dismal calamity is but just over, and you yourself are a witness to how Rome that commanded the world was astonished at the alarm of the Gothic trumpet, when that barbarous and victorious nation stormed her walls, and made her way through the breach. Where were then the privileges of birth, and the distinctions of quality? Were not all ranks and degrees leveled at that time and promiscuously huddled together? Every house was then a scene of misery, and equally filled with grief and confusion. The slave and the man of quality were in the same circumstances, and every where the terror of death and slaughter was the same, unless we may say the fright made the greatest impression on those who had the greatest interest in living." Many Romans were tortured into revealing the locations of their valuables. One was the 85-year-old Saint Marcella, who had no hidden gold as she lived in pious poverty. She was a close friend of Jerome, and he detailed the incident in a letter to a woman named Principia who had been with Marcella during the sack. " When the soldiers entered [Marcella's house] she is said to have received them without any look of alarm; and when they asked her for gold she pointed to her coarse dress to shew them that she had no buried treasure. However they would not believe in her self-chosen poverty, but scourged her and beat her with cudgels. She is said to have felt no pain but to have thrown herself at their feet and to have pleaded with tears for you [Principia], that you might not be taken from her, or owing to your youth have to endure what she as an old woman had no occasion to fear. Christ softened their hard hearts and even among bloodstained swords natural affection asserted its rights. The barbarians conveyed both you and her to the basilica of the apostle Paul, that you might find there either a place of safety or, if not that, at least a tomb." Marcella died of her injuries a few days later. The sack was nonetheless, by the standards of the age, restrained. There was no general slaughter of the inhabitants and the two main basilicas of Peter and Paul were nominated places of sanctuary. Most of the buildings and monuments in the city survived intact, though stripped of their valuables.
Refugees from Rome flooded the province of Africa, as well as Egypt and the East. Some refugees were robbed as they sought asylum, and Jerome wrote that Heraclian, the Count of Africa, sold some of the young refugees into Eastern brothels. "Who would believe that Rome, built up by the conquest of the whole world, had collapsed, that the mother of nations had become also their tomb; that the shores of the whole East, of Egypt, of Africa, which once belonged to the imperial city, were filled with the hosts of her men-servants and maid-servants, that we should every day be receiving in this holy Bethlehem men and women who once were noble and abounding in every kind of wealth but are now reduced to poverty? We cannot relieve these sufferers: all we can do is to sympathize with them, and unite our tears with theirs. [...] There is not a single hour, nor a single moment, in which we are not relieving crowds of brethren, and the quiet of the monastery has been changed into the bustle of a guest house. And so much is this the case that we must either close our doors, or abandon the study of the Scriptures on which we depend for keeping the doors open. [...] Who could boast when the flight of the people of the West, and the holy places, crowded as they are with penniless fugitives, naked and wounded, plainly reveal the ravages of the Barbarians? We cannot see what has occurred, without tears and moans. Who would have believed that mighty Rome, with its careless security of wealth, would be reduced to such extremities as to need shelter, food, and clothing? And yet, some are so hard-hearted and cruel that, instead of showing compassion, they break up the rags and bundles of the captives, and expect to find gold about those who are nothing than prisoners." The historian Procopius records a story where, on hearing the news that Rome had "perished", Honorius was initially shocked, thinking the news was in reference to a favorite chicken he had named "Rome": "At that time they say that the Emperor Honorius in Ravenna received the message from one of the eunuchs, evidently a keeper of the poultry, that Rome had perished. And he cried out and said, 'And yet it has just eaten from my hands!' For he had a very large cock, Rome by name; and the eunuch comprehending his words said that it was the city of Rome which had perished at the hands of Alaric, and the emperor with a sigh of relief answered quickly: 'But I thought that my fowl Rome had perished.' So great, they say, was the folly with which this emperor was possessed." After three days of looting and pillage, Alaric quickly left Rome and headed for southern Italy. He took with him the wealth of the city and a valuable hostage, Galla Placidia, the sister of emperor Honorius. The Visigoths ravaged Campania, Lucania, and Calabria. Nola and perhaps Capua were sacked, and the Visigoths threatened to invade Sicily and Africa. However, they were unable to cross the Strait of Messina as the ships they had gathered were wrecked by a storm. Alaric died of illness at Consentia in late 410, mere months after the sack. According to legend, he was buried with his treasure by slaves in the bed of the Busento river. The slaves were then killed to hide its location. The Visigoths elected Ataulf , Alaric's brother-in-law, as their new king. The Visigoths then moved north, heading for Gaul. Ataulf married Galla Placidia in 414, but he died one year later. The Visigoths established the Visigothic kingdom in southwestern Gaul in 418, and they would go on to help the Western Roman Empire fight Attila the Hun at the Battle of the Catalaunian Fields in 451. The Visigothic invasion of Italy caused land taxes to drop anywhere to one-fifth to one-ninth of their pre-invasion value in the affected provinces. Aristocratic munificence, the local support of public buildings and monuments by the upper classes, ended in south-central Italy after the sack and pillaging of those regions. Using the number of people on the food dole as a guide, Bertrand Lançon estimates the city of Rome's total population fell from 800,000 in 408 to 500,000 by 419. This was the first time the city of Rome had been sacked in almost 800 years, and it had revealed the Western Roman Empire's increasing vulnerability and military weakness. It was shocking to people across both halves of the Empire who viewed Rome as the eternal city and the symbolic heart of their empire. The Eastern Roman Emperor Theodosius II declared three days of mourning in Constantinople. Jerome wrote in grief, "If Rome can perish, what can be safe?"
The sack of 455 was the second of three sacks of Rome ; it was conducted by the Vandals, who were then at war with the usurping Western Roman Emperor Petronius Maximus. In the 440s, the Vandal king Genseric and the Roman Emperor Valentinian III, had betrothed their children, Huneric and Eudocia, to strengthen their alliance, reached in 442 with a peace treaty (the marriage was delayed as Eudocia was too young). In 455 Valentinian was killed, and Petronius Maximus rose to the throne. Petronius married Valentinian's widow, Licinia Eudoxia, and had his son Palladius marry Eudocia; in this way Petronius was to strengthen his bond with the Theodosian dynasty. This move, however, damaged Genseric's ambitions. The king of the Vandals claimed that the broken betrothal between Huneric and Eudocia was an invalidation of his peace treaty with Valentinian, and set sail to attack Rome. Before approaching the city, the Vandals knocked down all of the city's aqueducts. Upon the Vandal arrival, according to the chronicler Prosper of Aquitaine, Pope Leo I requested that Genseric not destroy the ancient city nor murder its inhabitants. Genseric agreed and the gates of Rome were thrown open to him and his men. Maximus, who fled rather than fight the Vandal warlord, was killed by a Roman mob outside the city, possibly together with his son Palladius. It is accepted that Genseric looted great amounts of treasure from the city, damaging objects of cultural significance such as the Temple of Jupiter Optimus Maximus by stripping away the gilt bronze roof tiles (hence the modern term vandalism), and also took Licinia Eudoxia and her daughters hostage. Eudocia later married Huneric. There is, however, some debate over the severity of the Vandal sack. The sack of 455 is generally seen as being more thorough than the Visigothic sack of 410, because the Vandals plundered Rome for fourteen days whereas the Visigoths spent only three days in the city. The cause of most controversy, however, is the claim that the sack was relatively "clean", in that there was little murder and violence, and the Vandals did not burn the buildings of the city. This interpretation seems to stem from Prosper's claim that Leo managed to persuade Genseric to refrain from violence. However, Victor of Vita records how many shiploads of captives arrived in Africa from Rome, with the purpose of being sold into slavery. Similarly, the Byzantine historian Procopius reports that at least one church was burnt down.