ENThis article is a biographical study of the Lithuanian socialist Vincas Kapsukas. It examines Kapsukas’s social background and his ideological evolution from Lithuanian nationalism to the espousal of socialism. An important phase of Kapsukas’s life was the period of imprisonment and exile that followed his participation in the Russian revolution of 1905. He chronicled his experiences of the Russian penal system in the book In the Tsar’s Prisons (first published in the United States in 1929). After his escape from Siberia, Kapsukas lived among the Lithuanian community in Bellshill, Scotland, many members of which were deported to Russia in 1917 and were later involved in the civil war in Siberia.