J.R.R. Tolkien’s academic field at Oxford when he became a professor of Anglo-Saxon was philology.
Philology is the historical study of languages and literary texts, especially through their vocabulary, grammar, sound changes, and written records. Tolkien’s professional work focused strongly on Germanic languages and medieval literature. He became Rawlinson and Bosworth Professor of Anglo-Saxon at Oxford in 1925, after teaching at the University of Leeds.
He later became Merton Professor of English Language and Literature in 1945. His scholarly expertise influenced his fiction: Tolkien constructed languages, developed historical sound patterns, and drew on works such as Beowulf, the Poetic Edda, and medieval legends. His invented languages were not merely decorative names; many were designed with related histories and changing forms.
Tolkien is often described simply as a literature professor, but philology more precisely identifies the linguistic-historical discipline central to his career. His academic life and creative writing were closely connected, though The Hobbit and The Lord of the Rings were not academic textbooks.