J.R.R. Tolkien’s academic specialty was philology.
Philology is the study of language through historical texts, including how words, sounds, and grammatical forms change over time. Tolkien was particularly interested in Germanic languages and literatures, Old English, Middle English, Gothic, Welsh, Finnish, and related linguistic traditions. His professional career was built primarily as a philologist and university teacher, not initially as a novelist.
His linguistic expertise directly influenced his creative work. Tolkien invented languages for his fictional peoples and developed their histories, sound systems, and relationships. He also used patterns from real languages and medieval literature to give Middle-earth cultural depth. Philology is sometimes confused with linguistics in general, but Tolkien’s work especially emphasized historical language study and the interpretation of old texts.