A related question was asked here: https://www.reddit.com/r/AskHistorians/comments/5mm271/why_does_beowulf_composed_in_old_english_take/?ref=search_posts
But I'm specifically interested in why an Anglo-Saxon epic contains no heroes from the ethnic groups that the epic belongs to. I suppose that Angles and Saxons considered themselves related to Danes and Geats, as Germanic peoples and might have some of that going there, similar to Virgil (a Roman) in the Aeneida with Greeks. But still, why does the most famous Anglo Saxon epic not feature any character who's an Angle or Saxon (or Jute)? Especially considering they warred against Danes pretty frequently. Is it because they considered themselves the inheritors of "those" Danes and Geats of the epic?
Edit: spelling.
It has to do with how the Anglo-Saxon nobility who would have been the audience for Beowulf viewed itself at the time the poem was composed. Only one copy of Beowulf survives today in a manuscript called the Cotton MS Vitellus A .xv (which you can see online here: http://www.bl.uk/manuscripts/FullDisplay.aspx?ref=cotton_ms_vitellius_a_xv), along with many more Anglo-Saxon poems. Someone sat down and physically copied the poem on parchment in a West Saxon scriptorium—a room where monks made books—around 1000 AD. This isn’t the first manuscript the original composer wrote it down on (what we call a “holograph manuscript”), but a copy. We know this because there are two different scribal hands in the whole book that Beowulf appears in, both characteristic of West Saxon scriptoriums around that time, and it was common for more than one monk to do the hard work of copying a manuscript. The poem's text is also mostly in the West Saxon dialect of Old English, but the occasional hint of Anglian makes scholars think it was copied from an Anglian source. The theory that it was first composed in East Anglia is backed up by the fact of the Sutton Hoo Ship Burial, an incredible archaeological find of artifacts including armor, weapons, and jewels that seem to match the very descriptions in Beowulf. Putting an exact date on the composition is harder, but it was probably after 680 AD when we first start seeing Germanic alliterative poetry, and probably before 800 AD, when Danish raids on the British Isles got started in such earnest that it’s hard to believe any Anglo-Saxon monastery or king would like celebrating the heroes of a culture that was pillaging them.
So, we have a poem composed in 680 – 800 AD for a Germanic warrior-nobility before tensions really escalated with their Scandinavian cousins. This is a society that would be mostly Christian at this point but still a distinctly Germanic culture and poetic tradition. At this point, the Angles, Saxons, and Jutes weren’t so far removed from their roots that they’d have forgotten the folklore they first brought over to the British Isles with them. This was also a culture with a strong tradition of oral poetry, meaning that poems were apt to get lifted and adapted from each other fairly easily before eventually getting “paralyzed” on parchment. That makes scholars like Mitchell and Robinson start to see Beowulf as less of a definitive poem composed for a certain occasion/person with any carefully-defined “Anglo-Saxon” identity written in it. Instead, they think it’s more likely it was made out of a tight-knit warrior-aristocracy that was more interested in kin ties than a sense of national identities, so they still could have appreciated a rather Scandinavian poem.
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