Duncan Forbes's time at Clare was initially short-lived, as in 1942 he was called up to fight in the Second World War; enlisting in the Seaforth Highlanders, he won the Military Cross while serving as a platoon commander at the Battle of Anzio.
[3] Returning to Clare in 1945, he was awarded a degree in history and was made a fellow of the college in 1947, remaining there for the rest of his life.
[2] Forbes edited Adam Ferguson's An Essay on the History of Civil Society for the University of Edinburgh Press in 1966.
In 1970 Pelican Books published the volumes of David Hume's History of Great Britain that covered the early Stuarts, to which Forbes wrote the introduction.
[6] Forbes' work on the Scottish Enlightenment led to one of his students, John Dunn, calling him "a Highlander in exile".