Serf

"A person in a condition of servitude or modified slavery, distinguished from what is properly called 'slavery' in that the services due to the master, and his power of disposal of his 'serf' are more or less limited by law or custom; In the 17th-18th century used (after French example) with reference to the contemporary condition of the lower class of cultivators of the soil in various countries of Europe, especially in parts of Germany, in Denmark, Poland, and Russia; chiefly with reference to Russia, where the serfs were not emancipated until 1861, while elsewhere in Europe serfdom ceased to exist early in the 19th century." (OED)

“All night the cell was crowded with prisoners who had lived and died there. They were broken-faced, greenish-gray men, with haunted eyes, scarred shaved heads and ragged bodies, crowding the cell. Many stared wordlessly at the fixer and he at them, their eyes lit with longing for life. If one disappeared two appeared in his place. So many prisoners, thought the prisoner, it’s a country of prisoners. They’ve freed the serfs, or so they say, but not the innocent prisoners. He beheld long lines of them, gaunt-eyed men with starved mouths, lines stretching through the thick walls to impoverished cities, the vast empty steppe, great snowy virgin forests, to the shabby wooden work camps in Siberia.”

Bernard Malamud, The Fixer (1966).