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. The Huns likely entered Western Asia 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. In the following years, the Huns conquered most of the Germanic and Scythian tribes outside of the borders of the Roman Empire. They also launched invasions of both the Asian provinces of Rome and the Sasanian Empire in 375. 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. From the 420s, the Huns were led by the brothers Octar and Ruga, who both cooperated with and threatened the Romans. 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. Attila appears to have killed his brother, and became sole ruler of the Huns in 445. 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 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. The following year, the Huns invaded Italy and encountered no serious resistance before turning back.
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 Huns themselves are usually thought to have disappeared after the death of his son Dengizich in 469. However, some scholars have argued that the Bulgars in particular show a high degree of continuity with the Huns. 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.
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.