There are a number of factors that contributed to the decline of the Huns, including:
- The rise of the Gothic and Bulgar tribes in the Balkans
- The death of Attila the Hun, which led to infighting among his sons and other Hunnic leaders
- The migration of the Huns' Germanic and Slavic subjects
- The Huns' excessive military campaigns and lack of a solid economic base
- The impact of diseases such as smallpox
By the end of the 5th century, the Huns had largely disappeared as a distinct group. Some of the remaining Huns were assimilated into other groups, such as the Goths and the Bulgars. Others may have migrated to Asia, where they eventually disappeared.