Well...Beowulf is a mighty knight and he heard that the king Hrothgar of Denmark and his men was being attack by Grendel and he hurriedly travel there and killed Grendel and he also killed the mother of Grendel snd after that he was given a prized from king Hrothgar and he returns to the place whare he came from and rule the kingdom there and he was attack by a great dragon and bited his neck.Beowulf died because of the poison of the great dragon.

I hope it help you a bit...:D