Katorga (Russian:ка́торга;IPA: [ˈkatərgə]; from medieval Greek: katergon, κάτεργον, "galley") was a system of penal labor in the Russian Empire. Prisoners were sent to remote penal colonies in vast uninhabited areas of Siberia and Russian Far East where voluntary settlers and workers were never available in sufficient numbers. The prisoners had to perform forced labor under harsh conditions.