Why does Beowulf make the journey to Heorot?

Danish sailors bring news of Grendel to King Hygelac of the Geats whose nephew (also named Beowulf, like King Hrothgar's father Beowulf Scylding) has a growing reputation for strength and monster-killing. Beowulf, supported by the wisest of his people, resolves to go to Hrothgar's aid and sets off by ship with fourteen companions.