Answer:
Beowulf
The son of Healfdene is Hrothgar who became the King of the Geats. During Hrothgar's reign, Grendel tormented the Geats people for twelve years by killing off Hrothgar's followers and generals.
Explanation:
In the epic poem titled "Beowulf," Grendel, a monster killed the followers and generals of Hrothgar. The situation became hopeless until Beowulf, an Anglo Saxon warrior volunteered to fight Grendel. Utilizing his battle prowess, Beowulf murdered Grendel and faced Grendel's mother who fought him in order to revenge her son's death in the hands of Beowulf. According to the poem, Beowulf was able to defeat Grendel's mother as well, thus ending the monstrous torment of the Geats people. Beowulf was later rewarded for this rescue with a kingly crown and succession.