King Hrothgar was a character in the Beowulf holonovel. His kingdom was attacked by Grendel, in reality an energy being that had captured Chakotay, Tuvok, and Harry Kim.
Hrothgar first killed someone at age eleven, and built a hall. He had fathered a daughter, Freya. By the time of the story, his underlings considered him old and desperate.
When The Doctor arrived to attempt to free his crewmates, Hrothgar welcomed him to his hall, since his daughter vouched for him. Hrothgar told The Doctor that his kingdom was in chaos due to the monster and that all joy had left the kingdom. He was advised by Unferth not to trust The Doctor. Hrothgar's daughter Freya romanced The Doctor and ultimately gave her life to save him, killed by a spear that was meant for him. (VOY: "Heroes and Demons")
Hrothgar was played by Michael Keenan.