Beowulf is an Old English poem from the Anglo-Saxon days of literature. Historically, the Anglo-Saxons did not have much in ways of entertainment (outside of battling and feasting). That said, epic tales, like Beowulf, were used to do a few things.
First, the tales were normally sung by scops in order to entertain the gatherers at celebrations or feasts. The tales were heroic in nature and highlighted the characteristics of a person who possessed the specific qualities (like honor, loyalty, and courage) revered by the society.
Second, tales such as Beowulf were meant to energize and bring out the characteristics in the younger generations who wished to go forth in battle and be fierce and successful warriors. By telling the tales of epic heroes, others would see the characteristics needed to be renowned in their own right.
Lastly, some epics (like Beowulf) may have been grounded in real stories about true heroes. As the stories were passed along and down, the stories tended to become embellished. Therefore, the story of Beowulf may be real, but altered enough to hide the identity of the real warrior with specific elements added for entertainment purposes.
Beowulf is a product of the same sweeping migrations that brought down the Roman empire and the poem is the fruit of a transition from paganism to Christianity as profound as the one that had transformed Rome. Nevertheless, it is a vertiginous thought to consider that Beowulf is set during the same period that Augustine wrote his Confessions and Jerome undertook his translation of the Bible and that it was composed in a land just a few centuries removed from Roman occupation. Although recent scholarship
has been directed primarily at uncovering traces of the monastic culture and residual Romanism of the Early Middle Ages in the poem and reconstructing some manner of precise historical context, its primary impact for readers has long been its absolute strangeness: the distance of its language from modern English; the lack of
familiarity with the places, names, and customs depicted in it; and even the mystery of its date, its provenance, its author, and its original audience.