The Fall of the Western Roman Empire (also called Fall of the Roman Empire or Fall of Rome) was the process of decline in the Western Roman Empire in which the Empire failed to enforce its rule, and its vast territory was divided into several successor polities. The Roman Empire lost the strengths that had allowed it to exercise effective control over its Western provinces; modern historians posit factors including the effectiveness and numbers of the army, the health and numbers of the Roman population, the strength of the economy, the competence of the Emperors, the internal struggles for power, the religious changes of the period, and the efficiency of the civil administration. Increasing pressure from invading barbarians outside Roman culture also contributed greatly to the collapse. Climate change has been suggested as a driver of the changes in some of these factors. The reasons for the collapse are major subjects of the historiography of the ancient world and they inform much modern discourse on state failure.
The Huns were a nomadic people who lived in Central Asia, the Caucasus, and Eastern Europe, between the 4th and 6th century AD. According to European tradition, they were first reported living east of the Volga River, in an area that was part of Scythia at the time; the Huns' arrival is associated with the migration westward of an Iranian people, the Alans. By 370 AD, the Huns had arrived on the Volga, and by 430 the Huns had established a vast, if short-lived, dominion in Europe, conquering the Goths and many other Germanic peoples living outside of Roman borders, and causing many others to flee into Roman territory. The Huns, especially under their King Attila, made frequent and devastating raids into the Eastern Roman Empire. In 451, the Huns invaded the Western Roman province of Gaul, where they fought a combined army of Romans and Visigoths at the Battle of the Catalaunian Fields, and in 452 they invaded Italy. After Attila's death in 453, the Huns ceased to be a major threat to Rome and lost much of their empire following the Battle of Nedao (454?). Descendants of the Huns, or successors with similar names, are recorded by neighbouring populations to the south, east, and west as having occupied parts of Eastern Europe and Central Asia from about the 4th to 6th centuries. Variants of the Hun name are recorded in the Caucasus until the early 8th century.
The Iberian War was fought from 526 to 532 between the Byzantine Empire and Sasanian Empire over the eastern Georgian kingdom of Iberia.
The Vandalic or Vandal War (Greek: Βανδηλικὸς Πόλεμος, Vandēlikòs Pólemos) was a conflict fought in North Africa (largely in modern Tunisia) between the forces of the Eastern Roman or Byzantine Empire and the Vandalic Kingdom of Carthage, in 533–534. It was the first of Justinian I's wars of reconquest of the lost Western Roman Empire.
The Vandals had occupied Roman North Africa in the early 5th century, and established an independent kingdom there. Under their first king, Geiseric, the formidable Vandal navy carried out pirate attacks across the Mediterranean, sacked Rome and defeated a massive Roman invasion in 468. After Geiseric's death, relations with the surviving Eastern Roman Empire normalized, although tensions flared up occasionally due to the Vandals' militant adherence to Arianism and their persecution of the Chalcedonian native population. In 530, a palace coup in Carthage overthrew the pro-Roman Hilderic and replaced him with his cousin Gelimer. The Eastern Roman emperor Justinian took this as a pretext to interfere in Vandal affairs, and after he secured his eastern frontier with Sassanid Persia in 532, he began preparing an expedition under general Belisarius, whose secretary Procopius wrote the main historical narrative of the war. Justinian took advantage of, or even instigated, rebellions in the remote Vandal provinces of Sardinia and Tripolitania. These not only distracted Gelimer from the Emperor's preparations, but also weakened Vandal defences through the dispatch of the bulk of the Vandal navy and a large portion of their army under Gelimer's brother Tzazon to Sardinia.
The Roman expeditionary force set sail from Constantinople in late June 533, and after a sea voyage along the coasts of Greece and southern Italy, landed on the African coast at Caputvada in early September, to Gelimer's complete surprise. The Vandal king gathered his forces and met the Roman army at the Battle of Ad Decimum, near Carthage, on 13 September. Gelimer's elaborate plan to encircle and destroy the Roman army came close to success, but Belisarius was able to drive the Vandal army to flight and occupy Carthage. Gelimer withdrew to Bulla Regia, where he gathered his remaining strength, including the army of Tzazon, which returned from Sardinia. In December, Gelimer advanced towards Carthage and met the Romans at the Battle of Tricamarum. The battle resulted in a Roman victory and the death of Tzazon. Gelimer fled to a remote mountain fortress, where he was blockaded until he surrendered in the spring.
Belisarius returned to Constantinople with the Vandals' royal treasure and the captive Gelimer to enjoy a triumph, while Africa was formally restored to imperial rule as the praetorian prefecture of Africa. Imperial control scarcely reached beyond the old Vandal kingdom, however, and the Moorish tribes of the interior proved unwilling to accept imperial rule and soon rose up in rebellion. The new province was shaken by the wars with the Moors and military rebellions, and it was not until 548 that peace was restored and Roman government firmly established.
The Gothic War between the Byzantine Empire during the reign of Emperor Justinian I and the Ostrogothic Kingdom of Italy took place from 535 until 554 in the Italian peninsula, Dalmatia, Sardinia, Sicily and Corsica. The war had its roots in the ambition of the East Roman Emperor Justinian I to recover the provinces of the former Western Roman Empire, which the Romans had lost to invading barbarian tribes in the previous century (the Migration Period).
The war followed the Byzantine reconquest of the province of Africa from the Vandals. Historians commonly divide the war into two phases:
In 554 Justinian promulgated the Pragmatic sanction which prescribed Italy's new government. Several cities in northern Italy held out against the Byzantines until 562. By the end of the war Italy had been devastated and depopulated. The Byzantines found themselves incapable of resisting an invasion by the Lombards in 568, which resulted in Constantinople permanently losing control over large parts of the Italian peninsula.
The Lazic War, also known as the Colchidian War or in Georgian historiography as the Great War of Egrisi (Georgian: ეგრისის დიდი ომი, Egrisis Didi Omi), was fought between the East Roman (Byzantine) Empire and the Sasanian Empire for control of the ancient Georgian region of Lazica. The Lazic War lasted for twenty years, from 541 to 562, with varying success and ended in a victory for the Persians, who obtained an annual tribute in exchange for ending the war. The Lazic War is narrated in detail in the works of Procopius of Caesarea and Agathias.
The Byzantine–Sasanian War of 572–591 was a war fought between the Sasanian Empire of Persia and the Eastern Roman Empire, termed by modern historians as the Byzantine Empire. It was triggered by pro-Byzantine revolts in areas of the Caucasus under Persian hegemony, although other events contributed to its outbreak. The fighting was largely confined to the southern Caucasus and Mesopotamia, although it also extended into eastern Anatolia, Syria, and northern Iran. It was part of an intense sequence of wars between these two empires which occupied the majority of the 6th and early 7th centuries. It was also the last of the many wars between them to follow a pattern in which fighting was largely confined to frontier provinces and neither side achieved any lasting occupation of enemy territory beyond this border zone. It preceded a much more wide-ranging and dramatic final conflict in the early 7th century.
In the last decade of the eighth century, Norse raiders sacked a series of Christian monasteries located in what is now the United Kingdom, beginning in 793 with a raid on the coastal monastery of Lindisfarne on the north-east coast of England.
From 865, the Norse attitude towards the British Isles changed, as they began to see it as a place for potential colonisation rather than simply a place to raid. As a result of this, larger armies began arriving on Britain's shores, with the intention of conquering land and constructing settlements there.
Great Heathen Army (865–78)