Seweryn was born in Pirkowicze near Drohiczyn (Polesie, Poland), the Wysłouch family manor.
In 1927 he graduated from the School of Law and Social Sciences of the Stefan Batory University in Vilnius and began to work there as an academic.
His career was interrupted by the outbreak of the Second World War, but he continued it from 1945 at the University of Wrocław as a professor.
During the inter-war period he was a member of the Senior Ramblers Club (Klub Włóczęgów Seniorów), a small, influential academic society linked to Marshal Józef Piłsudski and his government.
[2] In 1948 he took part in the organisation of the Regained Territories Exhibition and from 1949 to 1953 he presided over the Wrocław branch of the Western Institute, a scientific research society focusing on the Western provinces of Poland.