Beowulf (1999)

"This post-apocalyptic future story is based on the 8th century Saxon epic poem about the knight who battled a monster in a medieval castle. In this story, Beowulf is a wanderer who learns about a man-eating creature called Grendel which comes in the night to devour warriors trapped at the Outpost. The Outpost is ruled by Hrothgar. He has a daughter, whose husband may have been murdered by the Outpost's master of arms."

IMDB