Rome classified its poorest citizens by the only thing they could offer: children.
Roman authorities conducted a census every five years. Citizens were sorted into classes by property, which determined military duties and voting rights. Those who owned 11,000 asses or fewer fell below the lowest category for military service.1 The census listed their children instead of their property.
The Latin word proles meant offspring. Proletarius described a citizen whose only contribution to the state was producing the next generation of Romans.2
The word survived as a historical curiosity for centuries. Rousseau used the French form prolétaires in The Social Contract (1762).3 The Swiss economist Sismondi was the first to apply the term to industrial wage earners in the 1820s and 1830s.4
Karl Marx, who studied Roman law at Friedrich Wilhelm University in Berlin, adopted the term in the 1840s to describe the revolutionary working class. In The Communist Manifesto (1848), Marx and Engels wrote that society was splitting into two great hostile camps: bourgeoisie and proletariat.5
During Marx's lifetime, wage laborers formed a majority of the working population only in parts of northern Europe and the northeastern United States. Marx also coined Lumpenproletariat in 1850 to describe a class beneath the proletariat, people too disorganized for collective action.6
George Orwell borrowed the word in abbreviated form for his 1949 novel Nineteen Eighty-Four. The proles, as he called them, made up eighty-five percent of the population of Oceania, living beyond the surveillance that controlled party members.