 Ancient political philosophy is understood here to mean ancient Greek and Roman thought from the classical period of Greek thought in the fifth century BCE to the end of the Roman empire in the West in the fifth century CE, excluding the development of Jewish and Christian ideas about politics during that period. Political philosophy as a genre was invented in this period by Plato and, in effect, reinvented by Aristotle: it encompasses reflections on the origin of political institutions, the concepts used to interpret and organize political life such as justice and equality, the relation between the aims of ethics and the nature of politics, and the relative merits of different constitutional arrangements or regimes. Platonic models remained especially important for later authors throughout this period, even as the development of later “Hellenistic” schools of Greek philosophy, and distinctively Roman forms of philosophical adaptation, offered new frameworks for construing politics from a philosophical point of view. Engagement in these Greek and Roman traditions of political philosophy among late antique scholars continued through and beyond the eventual abdication of the last pretenders to the Roman imperial throne in the Western part of the empire in 476 CE, and further still among medieval scholars and their successors writing in Greek, Latin, Hebrew, and (later on) Arabic.