He was one of the most feared enemies of the Roman Empire constantly attacking at various locations in the east and the west but was never able to take the larger cities of Constantinople or Rome which began to negatively affect his image/reputation. He tried to invade Roman Gaul (France), and was also beaten. But the carnage to and from all these major cities was devastating and citizens of the Roman Empire were in an uproar that their leaders couldn’t stop Atilla from disrupting their lives.
He planned further campaigns against the Romans as he never gave up trying to sack Rome but died in 453 of strange circumstances. He was at a wedding feast where he was marrying yet another bride and all of a sudden his nose started bleeding and he fell to the floor and died. There’s much speculation regarding his death but poisoning was definitely one of the primary theories.
The Hunnic Empire only lasted a few years after Atilla died. A once close friend of his actually led the attack against the Huns and was able to topple the empire.