One possible reason may have been climate change, however, Peter Heather notes that in the absence of reliable data this is unprovable. The reasons for the Huns' sudden attack on the neighboring peoples are unknown. The Huns' sudden appearance in the written sources suggests that the Huns crossed the Volga River from the east not much earlier. Early history First conquests Ī suggested path of the Huns' movement westwards (labels in German) Other scholars have regarded both names as referring to a Germanic tribe, the Burgundi (Burgundians), although this identification was rejected by Maenchen-Helfen (who speculated that one or both names may have approximated an early Turkic ethnonym, such as " Vurugundi"). Ī tribe called the Ουρουγούνδοι Ourougoúndoi (or Urugundi) who, according to Zosimus, invaded the Roman Empire from north of the Lower Danube in 250 AD, may have been synonymous with the Βουρουγουνδοι Bourougoundoi, whom Agathias (6th century) listed among the Hunnish tribes. However, Maenchen-Helfen concedes that Ammianus Marcellinus referred to Ptolemy's report of the Khunnoi, when stating that the Huns were "mentioned only cursorily" by previous writers. Maenchen-Helfen and Denis Sinor also dispute the association of the Khunnoi with Attila's Huns. Thompson have claimed that the similarity of the ethnonyms Khunnoi and Hun were coincidental. (In the Koine Greek used by Ptolemy, Χ generally denoted a voiceless velar fricative sound hence contemporary Western Roman authors Latinised the name as Chuni or Chunni.) The Khunnoi lived "between the Bastarnae and the Roxolani", according to Ptolemy. The 2nd century AD geographer Ptolemy mentioned a people called Χοῦνοι Khunnoi, when listing the peoples of the west Eurasian steppe. It is possible that the Huns were directly or indirectly responsible for the fall of the Western Roman Empire, and they have been directly or indirectly linked to the dominance of Turkic tribes on the Eurasian steppe following the fourth century. Hyun Jin Kim has argued that the three major Germanic tribes to emerge from the Hunnic empire, the Gepids, the Ostrogoths, and the Sciri, were all heavily Hunnicized, and may have had Hunnic rather than native rulers even after the end of Hunnic dominion in Europe. However, some scholars have argued that the Bulgars in particular show a high degree of continuity with the Huns. The Huns themselves are usually thought to have disappeared after the death of his son Dengizich in 469. Hunnic dominion over Barbarian Europe is traditionally held to have collapsed suddenly after the death of Attila the year after the invasion of Italy. The following year, the Huns invaded Italy and encountered no serious resistance before turning back. Attila is traditionally held to have been defeated in Gaul at the Battle of the Catalaunian Fields, however some scholars hold the battle to have been a draw or Hunnic victory. He would go on to rule for the next eight years, launching a devastating raid on the Eastern Roman Empire in 447, followed by an invasion of Gaul in 451. Attila appears to have killed his brother and became sole ruler of the Huns in 445.
Upon Ruga's death in 435, his nephews Bleda and Attila became the new rulers of the Huns, and launched a successful raid into the Eastern Roman Empire before making peace and securing an annual tribute and trading raids under the Treaty of Margus. From the 420s, the Huns were led by the brothers Octar and Ruga, who both cooperated with and threatened the Romans. Under Uldin, the first Hunnic ruler named in contemporary sources, the Huns launched a first unsuccessful large-scale raid into the Eastern Roman Empire in Europe in 408. They also launched invasions of both the Asian provinces of Rome and the Sasanian Empire in 375.
In the following years, the Huns conquered most of the Germanic and Scythian barbarian tribes outside of the borders of the Roman Empire. The Huns likely entered Europe shortly before 370 from Central Asia: they first conquered the Goths and the Alans, pushing a number of tribes to seek refuge within the Roman Empire. The history of the Huns spans the time from before their first secure recorded appearance in Europe around 370 AD to after the disintegration of their empire around 469.