In 1920 Cowling was lecturing at the University of Leeds, as Assistant Lecturer in English Language under Tolkien and E.V. Gordon. In 1925, when Tolkien moved to the University of Oxford, Cowling was appointed Reader. He subsequently moved to Australia to take up the Chair of English at the University of Melbourne in 1928. The Tolkien and Cowling families remained friends; in 1938 they stayed with J.R.R. and Edith at Oxford when on sabbatical leave.
His wife Muriel (Mollie) maintained contact with the Tolkien family after her husband's death, and visited the Tolkiens in England on several occasions. During such a visit in 1955, Muriel was given signed copies of three volumes of The Lord of the Rings (in which Tolkien included a Tengwar inscription).
- G.H. Cowling 23 December 1934 (letter)