Prester John
He wrote "Between Islam and Christendom" (1983) from his lectures and articles, and collaborated with Edward Ullendorff on "Hebrew letters of Prester John" and in 1996 with Bernard Hamilton on "Prester John, the Mongols and the Ten Lost Tribes". He finished Professor Sir Hamilton Gibb's translation and annotation of "The Travels of Ibn Battuta" - a project which had taken, as Beckingham noted, longer than the travels of Ibn Battuta himself.