it for over a millennium". Aristotle systematically analyzed the different systems of rule that the numerous Greek city-states had and divided them into three categories based on how many ruled: the many (democracy/polity), the few (oligarchy/aristocracy), a single person (tyranny, or today: autocracy/monarchy). For Aristotle, the underlying principles of democracy are reflected in his work Politics: Decline, revival, and criticisms The Athenian democracy, in its two centuries of life-time, twice voted against its democratic constitution (both times during the crisis at the end of the Pelopponesian War of 431 to 404 BCE), establishing first the Four Hundred (in 411 BCE) and second Sparta's puppet régime of the Thirty Tyrants (in 404 BCE). Both votes took place under manipulation and pressure, but democracy was recovered in less than a year in both cases. Reforms following the restoration of democracy after the overthrow of the Thirty Tyrants removed most law-making authority from the Assembly and placed it in randomly selected law-making juries known as "nomothetai". Athens restored its democratic constitution again after King Philip II of Macedon (reigned 359-336 BCE) and later Alexander the Great (reigned 336–323 BCE) unified Greece, but it was politically over-shadowed by the Hellenistic empires. Finally, after the Roman conquest of Greece in 146 BCE, Athens was restricted to matters of local administration. However, democracy in Athens declined not only due to external powers, but due to its citizens, such as Plato and his student Aristotle. Because of their influential works, after the rediscovery of classics during the Renaissance, Sparta's political stability was praised, while the Periclean democracy was described as a system of rule where either the less well-born, the mob (as a collective tyrant), or the poorer classes held power. Only centuries afterwards, after the publication of A History of Greece by George Grote from 1846 onwards, did modern political thinkers start to view the Athenian democracy of Pericles positively. In the late 20th century scholars re-examined the Athenian system of rule as a model of empowering citizens and as a "post-modern" example for communities and organizations alike. Rome Rome's history has helped preserve the concept of democracy over the centuries. The Romans invented the concept of classics and many works from Ancient Greece were preserved. Additionally, the Roman model of governance inspired many political thinkers over the centuries, and today's modern (representative) democracies imitate more the Roman than the Greek models. The Roman Republic Rome