Because he was the 5th grandchild of his grandfather and namesake with the first names Hendrik Bernardus, his parents decided to call him by the nickname Quintus ("Five") to distinguish him from his cousins; he was known as Quintie Thom throughout his life.

He continued his studies in history in Germany at the Friedrich Wilhelms Universität in Berlin (1928–1929), at the Sorbonne in Paris (1930) and in Amsterdam, researching his doctoral thesis, which he completed on his return to Stellenbosch.

He received honorary memberships of the following organisations: For 18 years he was chairman of the FAK (Federasie van Afrikaanse Kultuurvereniginge) and he was a sought after speaker.

The FAK was a front for the secret organisation the Afrikaner Broederbond of which Thom was a member and a chairperson from 1952 to 1960 (Wilkins & Strydom, 1978: A28; Google) He served as Administrator of the Woordeboek van die Afrikaanse Taal (WAT).

Professor HB Thom (Editors: DJ Kotze, Bun Booyens, JJ Oosthuysen and GPJ Trumpelmann), Stellenbosch University, 1969.