Tolkien’s academic specialty at Oxford University, where he taught from 1925, was Anglo-Saxon.
Tolkien became Rawlinson and Bosworth Professor of Anglo-Saxon at the University of Oxford in 1925. The field, now often called Old English studies, examines the language and literature of England before the Norman Conquest, including works such as Beowulf.
His professional knowledge strongly influenced his fiction. Tolkien paid close attention to the history of words, sound changes, poetic forms, and relationships among Germanic languages. These interests helped shape the names, languages, legends, and cultures of Middle-earth.
Tolkien later became Merton Professor of English Language and Literature at Oxford in 1945. His academic work was not separate from his imaginative writing: his celebrated 1936 lecture “Beowulf: The Monsters and the Critics” helped redirect scholarly attention toward the poem’s artistic structure and monsters.
The term Anglo-Saxon here refers to the academic study of Old English language and literature, not to a fictional subject from Tolkien’s books.