In literary works he becomes king of Gealand when their king Hygealac and his son die (Beowulf, lines 2250). In the works he returns to his homeland after freeing the Danes from Grendel and his mother. He does so and is considered a noble, respectable and faithful king. Although in the film Hrothgar is obviously affected by recent events, and when he leaves makes Beowulf his heir, he then commits suicide by stepping off a ledge into the mead hall, making Beowulf king of Denmark. Not exactly a noble or respectful way to take power especially when Hrothgar had loyalists