People have their own definition of a “hero”, but Joseph Campbell created a step by step process a hero has to go through to be classified as a hero. Examples would be the “call of duty” and how quickly he answers to that call. Beowulf, when he heard about the torture in Denmark, made his way there to save their people. That act by itself would be classified as heroic to modern day people.
However, there are categories of Campbell's requirements that Beowulf does