Final answer:
The Huns disappeared from history due to Attila's death, leading to a power vacuum and subsequent military defeat, ultimately leading to their integration into other societies.
Step-by-step explanation:
The Huns essentially disappeared from history after their peak due to leadership collapse following Attila's death in 453 and subsequent military defeats. The Hunnic Empire, which had grown significantly under Attila's rule, causing massive migrations and adding pressure to the frontiers of the Roman Empire, began to crumble rapidly without his leadership. Germanic tribes, who had been subjects of the Huns, allied with the remnants of the Roman army to defeat the Huns, leading to the dissolution of their empire. Many of the Huns integrated into other societies, marrying into local populations, and leaving no distinct trace of a Hunnic state behind.