Was Beowulf based on a true story?

Its not specified specifically but some say it is some say its not.

Answer:
A story based on ogres, trolls, dragons, and heros that can survive under water etc. is not likely to be based on truth. Like Texas Chainsaw Massacre where the true bits are that there is a Texas and they do make chainsaws, the truth in Beowulf is that the wandering hero was a figure in many stories, Denmark and the other lands did exist and swords and armour were used in fighting.