R.B. McCallum of Pembroke College, Oxford, wrote on political history and was a frequent attendee of Inklings sessions.
"R. B. McCallum: The Master Inkling,"
Mythlore: A Journal of J.R.R. Tolkien, C.S. Lewis, Charles Williams, and Mythopoeic Literature: Vol. 23
, Article 4.
Available at: http://dc.swosu.edu/mythlore/vol23/iss3/4