J.R.R. Tolkien’s Oxford academic field was philology.
Philology is the historical study of languages and texts, especially through their development, sounds, forms, and written records. Tolkien specialized in Germanic languages and medieval literature, including Old English, Middle English, Old Norse, and related traditions. His academic expertise shaped both his scholarship and his fictional languages.
Tolkien held the Rawlinson and Bosworth Professorship of Anglo-Saxon at Oxford from 1925 to 1945. He then became Merton Professor of English Language and Literature, a position he held until 1959. His knowledge of historical language helps explain the layered names, invented word histories, and linguistic relationships found throughout Middle-earth. Philology is broader than simply translating old texts or studying modern grammar.