Although born in Latvia, Henry Gelsen grew up in Germany, where he attended a municipal German primary school in Riga and the German Gymnasium in Kuldiga, gaining a 'Maturity Certificate'. After World War II he and his mother lived in various Displaced Persons' camps in West Germany, during which time he took part in cabarets and itinerant theatres and worked with the Municipal Theatre in Lubeck as an actor. They migrated to South Australia, where he gained a Bachelor of Arts degree (Hons), between 1954 and 1958, and a Master of Arts degree in 1964 from the University of Adelaide.
He worked variously as a logger, a police interpreter, a tram conductor, a postal clerk, a migrant adviser with the Commonwealth Bank and a research assistant at Flinders University. In his later years, he was a librarian with the Barr Smith Library at the University of Adelaide. He was a member of the Multilingual Authors Association of South Australia and read his work at several Adelaide Arts Festivals. He wrote in German, Latvian and English and his work was published in German and English. With Trevor Fennell from Flinders University he published A Grammar of Modern Latvian (c. 1980).
