Parkes was a student of
Neil Ripley Ker and wrote his B.Litt. thesis on the
secretary hand. From 1964 to 1971 he was a lecturer in the English Faculty of the university and from 1965 to 1997 he was a fellow at
Keble College, Oxford, and after Neil Ker's retirement university reader in palaeography a post he held 1993-96; he latterly held a personal chair in palaeography in the University of Oxford (1996- ). At Keble he taught Old and Middle English language and literature. Among his important individual achievements are the dating of the Oxford MS. of
The Song of Roland and his work on early manuscripts of the
Canterbury Tales (with Ian Doyle), still considered a standard. His 1969 book
English Cursive Book Hands, 1250-1500 is "the authoritative account", according to David Ganz, His work on punctuation (
Pause and Effect: an Introduction to the History of Punctuation in the West, 1993) focuses on "visual reading aids" and was highly influential. His books have glossaries which demonstrate how precisely he used language. He compiled a catalogue of Keble College's medieval manuscripts which was published in 1979 by Scolar Press, London. Parkes was elected to the Comité international de paléographie latine in 1986 and was a corresponding fellow of the
Medieval Academy of America from 1992. He died on 10 May 2013. ==References==