Mark was one of four brothers: Adolf (1905–1947; died in a Siberian prison camp), Albert (1907–1945; killed as a Forest Brother) and Aksel (1913–2014), who was an agronomist, journalist and Estonian Minister of the Interior in exile between 1962 and 1992.

In 1940, after the occupation of Estonia, he was a secretary of Tartu University for a short period, but left on the recommendation of the rector Hans Kruus.

In 1944 Mark moved to Sweden, where he was an assistant at the National Committee of Foreigners.

In 1998, Mark was awarded the honorary Doctor of Law degree by Tartu University.

Further, he was made an Honorary Member of the Estonian Literature Society, given the Golden Badge of the Estonian National Foundation, the I Class Gold Order of Merit of the Republic of Poland, and the II Class Order of the National Coat of Arms of the Republic of Estonia.