Old English
From Tolkien Gateway
Old English (sometimes called Anglo-Saxon) was the ancestor language of modern English. It was also the mother language of characters Ælfwine and Eriol.
Tolkien was a professor of Anglo-Saxon at at Pembroke College from 1925 to 1945. He was strongly influenced by Anglo-Saxon literature such as Beowulf and favoured especially the Mercian dialect. Tolkien wrote in Anglo-Saxon several texts of his legendarium, which he (fictionally) attributed to Ælfwine.
For Lord of the Rings, he used several Anglo-Saxon names and words, which represented Rohirric, the language of the Rohirrim.
