The main theme of Beowulf is heroism. This involves far more than physical courage. It also means that the warrior must fulfil his obligations to the group of which he is a key member. There is a clear-cut network of social duties depicted in the poem. The king has an obligation to behave with generosity. He must reward his thanes with valuable gifts for their defense of the tribe and their success in battle. This is why King Hrothgar is known as the "ring-giver." He behaves according to expectations of the duties of a lord when he lavishly rewards Beowulf and the other Geat warriors for ridding the Danes of Grendel's menace.
But the thanes have their obligations too. (A thane is a warrior who has been rewarded by his king with a gift of land.) They must show undivided loyalty to their lord. Only in this way can the society survive, because the world depicted in Beowulf is a ruthless and dangerous one.
The warriors must be prepared for battle at all times. Only in the mead-hall is there any respite from the dangers of the world outside. As Seamus Heaney writes in his introduction to the poem: "Here [in the mead-hall] is heat and light, rank and ceremony, human solidarity and culture" (p. xv). This is why the coming of Grendel is so traumatic for the Danes. They are being attacked in their own sanctuary.
Beowulf is the greatest of the heroes depicted in the poem not only because he has the greatest prowess in battle. He also perfectly fulfills his social obligations. He has the virtues of a civilized man, as well as the strength of the warrior. He looks after his people and is always gracious and kind. The following lines are typical...