Topics: Beowulf - Wikipedia
The full poem survives in the manuscript known as the Nowell Codex. It has no title in the original manuscript, but has become known by the name of the story's protagonist.  In 1731, the manuscript was badly damaged by a fire that swept through Ashburnham House in London that had a collection of medieval manuscripts assembled by Sir Robert Bruce Cotton.  The Nowell Codex is currently housed in the British Library.
In Denmark, recent archaeological excavations at Lejre , where Scandinavian tradition located the seat of the Scyldings, i.e., Heorot , have revealed that a hall was built in the mid-6th century, exactly the time period of Beowulf.  Three halls, each about 50 metres (160 ft) long, were found during the excavation. 
The majority view appears to be that people such as King Hroðgar and the Scyldings in Beowulf are based on real historical people from 6th-century Scandinavia.  Like the Finnesburg Fragment and several shorter surviving poems, Beowulf has consequently been used as a source of information about Scandinavian personalities such as Eadgils and Hygelac, and about continental Germanic personalities such as Offa , king of the continental Angles.