Philology, the study of comparative and historical linguistics, especially of the medieval period, had a major influence on J. R. R. Tolkien's fantasy world of Middle-earth. He was a professional philologist, and made use of his knowledge of medieval literature and language to create families of Elvish languages and many details of the invented world.
Among his medieval sources for Middle-earth are Beowulf, which he used in many places; his philological study of the Old English word Sigelwara, which may have inspired the Silmarils, Balrogs, and the Haradrim; and his research on an inscription at the temple of Nodens, which seems to have led to Celebrimbor Silver-hand, maker of Rings of Power, to Dwarves, and to the One Ring itself.
His use of his philological understanding of language in the construction of his Middle-earth legendarium was pervasive, beginning with his families of Elvish languages. From there, he created elements of story, including the history and geography of Middle-earth, the names of people and places, and eventually a complete mythology.
Context
From his schooldays, J. R. R. Tolkien was in his biographer John Garth's words "effusive about philology"; his schoolfriend Rob Gilson called him "quite a great authority on etymology". Tolkien was a professional philologist, a scholar of comparative and historical linguistics. He was especially familiar with Old English and related languages. He remarked to the poet and The New York Times book reviewer Harvey Breit that "I am a philologist and all my work is philological"; he explained to his American publisher Houghton Mifflin that this was meant to imply that his work was "all of a piece, and fundamentally linguistic [sic] in inspiration. ... The invention of languages is the foundation. The 'stories' were made rather to provide a world for the languages than the reverse. To me a name comes first and the story follows."
The Tolkien scholar Verlyn Flieger writes that Tolkien's "profession as philologist and his vocation as writer of fantasy/theology overlapped and mutually supported one another", in other words that he "did not keep his knowledge in compartments; his scholarly expertise informs his creative work." This expertise was founded, in her view, on the belief that one knows a text only by "properly understanding [its] words, their literal meaning and their historical development." She states that he skilfully exploited different characters' language styles to situate them geographically as well as in their specific culture and their psychological makeup, commenting that "One can imagine a seventy-page essay centuries hence on 'Tolkien as a Philologist: The Lord of the Rings".
Medieval sources
Beowulf
Tolkien was an expert on Old English literature, especially the epic poem Beowulf, and made many uses of it in The Lord of the Rings. For example, Beowulfs list of creatures, , "Ettens [giants] and Elves and demon-corpses", contributed to his creation of some of the races of beings in Middle-earth. He derived the Ents from a phrase in another Old English poem, Maxims II, , "skilful work of giants"; the Tolkien scholar Tom Shippey suggests that Tolkien took the name of the tower of Orthanc (orþanc) from the same phrase, reinterpreted as "Orthanc, the Ents' fortress". The word occurs again in Beowulf in the phrase , "[a mail-shirt, a] cunning-net sewn, by a smith's skill": Tolkien used searo in its Mercian form *saru for the name of Orthanc's ruler, the wizard Saruman, "cunning man", incorporating the ideas of skill and technology into Saruman's character. He made use of Beowulf, too, along with other Old English sources, for many aspects of the Riders of Rohan: for instance, their land was the Mark, a version of the Mercia where he lived, in Mercian dialect *Marc.
In a review of an article about placenames and archaeology, Tolkien wrote that the phrase on fāgne flōr, "on the bright-patterned floor", occurs in Beowulf, line 725. He commented that it "might be guessed to mean paved or even tessellated floor." Tolkien, describing himself rhetorically as "the philologist", notes that the Oxfordshire village of Fawler was in 1205 named Fauflor; that he would wonder if that meant there was a Roman villa nearby; and that "the archaeologist" would reply that there was indeed one "with a tessellated pavement" near there, the large and luxurious North Leigh Roman Villa. The folklorist and Tolkien scholar Dimitra Fimi writes that the Beowulf lines are definitely echoed in Tolkien's description of the hall of King Théoden of Rohan in The Lord of the Rings, and "perhaps even this image of the real floor" too.