The poem, with historical annotation and cultural references.
A scene from "Beowulf"
Beowulf was an ancient Earth epic poem, about a hero by the same name. Set during in 6th century Denmark, the poem describes Beowulf's fight against the water monster, Grendel, his victory over a dragon, and ultimately his death and funeral.
Additional characters in the epic included Freya, Unferth, and King Hrothgar.
In 2371, Harry Kim participated in a Beowulf holodeck program where he assumed the title role.
While he was playing the program, the USS Voyager was invaded by photonic lifeforms from a nearby protostar; these beings became lodged in the holodeck and caused three crew members, including Kim, to disappear. Voyager's Doctor was sent into the program (for his first away mission) to recover the missing people. (VOY: "Heroes and Demons")
According to the Star Trek Encyclopedia, 4th ed., vol. 1, p. 78, Beowulf was an ancient English epic poem probably written in the 8th century. This poem drew from Scandinavian history and folklore
Winrich Kolbe has commented that he sees DS9: "Blood Oath" as being like Beowulf. (The Deep Space Log Book: A Second Season Companion [page number? • edit])