Callipolis, the city ruled by philosopher-kings in Plato’s Republic, bears a strong resemblance to the regime of the so-called Thirty Tyrants—the brutal oligarchy, led by Plato’s cousin Critias and (in a lesser office) his uncle Charmides, that came to power after the Athenian surrender in 404. There is good reason to believe that Plato’s brother Glaucon, Socrates’ main interlocutor in the Republic, was a supporter of the oligarchy, and may have died alongside Critias and Charmides in the decisive battle that overthrew the Thirty. Howland’s talk will explore how this historical context helps us to make sense of the argument and action of Plato’s Republic.