From Wikipedia

Beowulf & the Anglo-Saxons

The events described in the poem take place in the late 5th century, after the Anglo-Saxons had begun migration and settlement in England, and before the beginning of the 7th century, a time when the Saxons were either newly arrived or in close contact with their fellow Germanic kinsmen in Scandinavia and Northern Germany. The poem could have been transmitted in England by people of Geatish origins. It has been suggested that Beowulf was first composed in the 7th century at Rendlesham in East Anglia, as Sutton Hoo also shows close connections with Scandinavia, and also that the East Anglian royal dynasty, the Wuffings, were descendants of the Geatish Wulfings. Others have associated this poem with the court of King Alfred, or with the court of King Canute.

The main protagonist, Beowulf, a hero of the Geats, comes to the aid of Hrothgar, the king of the Danes, whose great hall, Heorot, is plagued by the monster Grendel. Beowulf kills both Grendel and Grendel's mother, the latter with a magical sword.

Later in his life, Beowulf is himself king of the Geats, and finds his realm terrorized by a dragon whose treasure had been stolen from his hoard in a burial mound. He attacks the dragon with the help of his thegns, but they do not succeed. Beowulf decides to follow the dragon into its lair, at Earnanæs, but only his young Swedish relative Wiglaf dares join him. Beowulf finally slays the dragon, but is mortally wounded. He is buried in a tumulus by the sea.

Beowulf is considered an epic poem in that the main character is a hero who travels great distances to prove his strength at impossible odds against supernatural demons and beasts. The poem also begins in medias res ("into the middle of affairs") or simply, "in the middle", which is a characteristic of the epics of antiquity. Although the poem begins with Beowulf's arrival, Grendel's attacks have been going on for some time. The poet who composed Beowulf, while objective in telling the tale, nonetheless uses a certain style to maintain excitement and adventure within the story. An elaborate history of characters and their lineages are spoken of, as well as their interactions with each other, debts owed and repaid, and deeds of valor.