Mythology is key to understanding Beowulf. As I told my colleague’s students in a recent guest lecture, MYTHIC STRUCTURES typical such those as articulated in, for example, Snorri Sturluson’s thirteenth-century Prose Edda, function as follows.
Gods create Middle-Earth, building a wall to push away monsters, giants and frost ogres to the borders of the world. To celebrate and contain a space of peace they build a palace.
Eventually, chaos monsters transgress the borders, invade the space of peace (the palace), overcome the gods, and bring about the end of the world.
STRUCTURES IN SAGA
On the level of saga, this structure is played out within the scope of a nation. You can read about Frothi here. He rules Denmark at the time of Emperor Augustus when peace reigns over the whole world. “No man injured another, even although he was confronted with the slayer of his father or brother, free or in bonds. Neither were there any thieves or robbers, so that a gold ring lay untouched for a long time on the Heath of Julling.” Frothi’s peace and prosperity is overrun by giant women who grind out an army with a mill: “With that the Peace of Frothi came to an end.”
STRUCTURES IN BEOWULF
Scyld Scefing carves out a peaceful land. The border area is where monsters such as Grendel and his mother lurk. A hall is built by Hrothgar to celebrate the exclusion of such bad characters. But the joy is doomed to imminent sorrow.
The hall is invaded at night. Ultimately the nation is destroyed and dissolved. Beowulf rules for fifty years successfully (2732b-39a), but after he is killed, his kingdom is doomed (3014-27). The Lay of the Last Survivor expresses this sense of impending doom for once glorious kingdoms poignantly and succinctly2262b-66). All cultural artifacts will eventually tarnish and decay (lines 2255-6).
The walls will be destroyed. The gold-adorned walls will be covered in gore and blood.
 Snorri Sturluson, The Prose Edda, Jean I. Young, trans. (Berkeley: University of California Press, 1954): 118.
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