Servius was one of Rome’s last kings before the formation of the Roman Republic, and he ruled from 575 to 535 BCE. He famously did away with the existing class system in Rome, which was based on tribal affiliations, and instead divided the Roman people into different classes based on wealth. He also redesigned the comitia system in parallel with these new class distinctions, giving the most power (and military responsibility) to the wealthy and the least to the poor. In Book IV, Rousseau argues that Servius’s system was effective, if imperfect, and that it laid the foundation for popular sovereignty to emerge in Rome.