J.R.R. Tolkien translated Beowulf into modern English in his scholarly work.
Beowulf is an Old English poem about the hero Beowulf, who fights Grendel, Grendel’s mother, and a dragon. Tolkien produced a prose translation during the 1920s, but it was not published during his lifetime. His translation was eventually published in 2014 as Beowulf: A Translation and Commentary, edited by Christopher Tolkien.
Tolkien was also a major Beowulf scholar. His 1936 lecture “Beowulf: The Monsters and the Critics” argued that the poem’s monsters were central to its artistic design rather than distractions from its historical value. The lecture had a lasting influence on Beowulf studies.
The other options are also important Old and Middle English works, and Tolkien studied several medieval texts. Sir Gawain and the Green Knight was especially significant to him, but it is a Middle English romance, while Beowulf is an Old English heroic poem.