To try to penetrate the darkness of the five centuries which lie behind the extant MS by fitting together such fragments of illustrative information as can be obtained, and by using the imagination to bridge the gaps, has been the business of three generations of scholars distributed among the ten nations of Germanic speech. A whole library has been written around our poem, and the result is that this book cannot be as simple as either writer or reader might have wished.
The story which the MS tells us may be summarized thus: Beowulf, a prince of the Geatas, voyages to Heorot, the hall of Hrothgar, king of the Danes; there he destroys a monster Grendel, who for twelve years has haunted the hall by night and slain all he found therein. When Grendel's mother in revenge makes an attack on the hall, Beowulf seeks her out and kills her also in her home beneath the waters. He then returns to his land with honour and is rewarded by his king Hygelac. Ultimately he himself becomes king of the Geatas, and fifty years later slays a dragon and is slain by it. The poem closes with an account of the funeral rites.
Fantastic as these stories are, they are depicted against a background of what appears to be fact. Incidentally, and in a number of digressions, we receive much information about the Geatas, Swedes and Danes: all which information has an appearance of historic accuracy, and in some cases can be proved, from external evidence, to be historically accurate.