Why did Beowulf go to Denmark?

Beowulf goes to Denmark to help Hrothgar, the king of the Danes, defeat a monster named Grendel. Grendel has been terrorizing the kingdom for 12 years, attacking the Danes in their sleep and devouring them. Beowulf is a legendary hero from Geatland, and he has heard of Grendel's attacks and come to Denmark to offer his help. Beowulf is the only person who can defeat Grendel, as he is the only one who has the strength and courage to face the monster.