J.R.R. Tolkien studied and lectured extensively about the Old English poem Beowulf.
Beowulf is an epic poem about a hero who fights the monster Grendel, Grendel’s mother, and later a dragon. Its surviving manuscript dates from around the early eleventh century, although the poem itself was composed earlier in the Old English period.
Tolkien was a philologist and an important scholar of Old and Middle English. His 1936 lecture “Beowulf: The Monsters and the Critics” argued that the poem’s monsters were central to its artistic design rather than embarrassing distractions from historical material.
His scholarship influenced modern approaches to the poem and also helped explain why heroic conflict, dragons, ancient languages, and layered legends mattered so much in his fiction. Tolkien translated Beowulf into modern English, but that translation was published posthumously in 2014 as Beowulf: A Translation and Commentary. Other Old English poems were also important to him, but Beowulf was his most famous scholarly subject.