His grandfather was a well-known brass founder and Provost of Greenock, where the family had a connection with James Watt, the engineer.
He then completed a classics degree at Pembroke College, Oxford, with an open scholarship, graduating with first-class honours in 1890.
[3] Five years later, the chair was split and he was appointed Professor of Classics, serving until he retired in 1933.
During this period, he edited Samuel Johnson's Lives of Milton and Addison (1900) and produced a collection of Lord Byron's poetry (1904).
[4] In retirement, Duff continued to write; with Arnold Mackay Duff (his son [1900-1976]), he produced Minor Latin Poets: With Introductions and English Translations in 1934 and two years later completed Roman Satire: Its Outlook on Social Life (published by Cambridge University Press).