Why did legends arise that Frederick II had not really died?

When Frederick II died unexpectedly in 1250, the news deeply shocked Europe, leading to widespread disbelief and the emergence of various legends regarding his survival.1

These myths arose largely because of the intense political and religious turmoil that defined his reign, particularly his protracted struggle with the papacy. Because he had been a polarizing figure—branded as a precursor to the Antichrist by his enemies and hailed as a messiah by his supporters—many found it difficult to accept his death as final.1

The legends took different forms based on regional hopes and fears:
* In Sicily, it was rumored that he had been conveyed to the Aetna volcano.1
* In Germany, a belief spread that he was not dead but rather "encapsuled" in a mountain, waiting to return as a "latter-day emperor" to punish the worldly church and restore the Holy Roman Empire to peace.1

These stories reflected a desperate desire for the stability and imperial authority he represented, similar to the later legends surrounding his grandfather, Frederick I Barbarossa.123