The Italians imprisoned him in 1918, and upon his release, in 1919, he enrolled at the University of Graz where he studied German and English and received his doctorate with a thesis on Arno Holz, directed by Bernhard Seuffert.
There he met Robert Priebsch, a German professor (author of Handschriften in England, Erlangen 1896-1901), whose daughter Hannah he married in 1931.
Closs admired Priebsch greatly, and edited of some of his unpublished work, including Letter from Heaven (1936) and Christi Leiden in einer Vision geschaut (1936),[1] as well as his correspondence with the linguist Elias von Steinmeyer.
[3] The Dictionary of National Biography describes him thusly: After World War II, Closs played an important part in the reestablishment of cultural relations between Germany and England, especially between the war-damaged cities of Bristol and Hannover.
He led an "expedition" of five men representing educational, governmental, and commercial organizations from Bristol on a visit to Hannover to investigate possible aid projects.
His memorial service, on 2 November 1990 at St Mary Redcliffe, was described as "magnificent...framed with the music of Mozart", with the burgomaster of Hannover as one of the participants.