“First, the only manuscript that we have of Beowulf is from around 1000.  So your museum curator is only partially correct.  The manuscript is not from the 11th century, but rather from around the turn of the 11th century.  This means that the manuscript comes from Anglo-Saxon England, not post-Norman invasion (1066).  While the Anglo-Saxon world of 1000 was much more stable, centralized, and Christian that that of 600, it is culturally more closely related to 600 than post-1066.  The 11th century experienced much change, development, and growth, and so to equate early-11th with the late-11th century would be like comparing the early-20th with the late-20th century.

Second, just because the manuscript is from the turn of the 11th century does not mean the world it relates to us is from that period.  The world of Beowulf, with exception of some forced Christian ideas inserted (probably) from the monk copying the manuscript, is very much the world of Bede.  There is no scholarly consensus of when the poem was composed, dates ranging from around 650 to 1000.  Most scholarship early in the 20th century supposes an early composition; however, post-1980 scholarship is more cautious about the dating.  Regardless of the exact date of composition, it still portrays well the world of Anglo-Saxon England circa 600 (or the world of pre-Viking norse, or the further side of the Rhine).  Even if there is no oral/written version Beowulf before, say, 1000 (which I highly doubt), I would still say that Bede would have recognized the world therein, and that it was completely appropriate to have Charlie in a “play” about Beowulf while visiting the sites of Bede.Finally, the world of Beowulf is actually not England proper, but rather Scandinavia, with Beowulf from among the various Germanic tribes from modern-day Sweden and Heorot from modern-day Denmark.  And the world that Beowulf portrays for pre-Viking Scandinavia circa 600 is accurate, and we can even cull some historical information from the text like several of the princely and noble families named and listed who were pre-Viking norse families.  Even so, it is a piece of epic literature, and thus not simply a “historical” source; however, the world it imagines is very much accurate, with its heavy emphasis on:

• Fate and pagan (and in the poem sometimes the Christian God is merely a substitute for fate, the two terms being often interchangeable)
• Evil (Grendel, Grendel’s mom, and the dragon) as something external to the individual and the community, which has to be defeated (as oppose to evil inherent in humanity, like sin)
• A society built on heroism, honor, and vengeance (One of the best descriptions of the Germanic warrior code comes from Beowulf, see: “Beowulf, son of Ecgtheow, spoke: / ‘Wise sir, do not grieve.  It is always better / to avenge dear ones than to indulge in mourning. / For every one of us living in this world / means waiting for our end.  Let whoever can / win glory before death.  When a warrior is gone, / that will be his best and only bulwark … Bear up / and be the man I expect you to be.'” 1383-1389, 1395-1396)
• The importance of the warrior troop (even though Beowulf does most of the fighting, he does not do it without his troop.  Compare this with, say Sir Gawain and the Green Knight or some other Arthurian tale where the characters are often waging their battles alone, and often their battles revolve around virtue and vice), celebrating in the mead hall with one’s troop, and the gift giving to those loyal to you.

Thus Beowulf represents well an early-medieval Germanic culture, regardless of geographical location–Scandinavia, across the Rhine, or even Anglo-Saxon England.”