About 3,190 years ago, a merchant in Emar, a trading outpost in what is now northern Syria, sent a desperate letter to his boss, Urtenu, who lived in the rich metropolis of Ugarit, a city-state on the coast of Syria. “There is famine,” he wrote. “If you do not quickly arrive here, we ourselves will die of hunger.”

A long drought had left the hinterlands around Ugarit in a state of famine, wars were brewing, and there were likely plagues as well. Urtenu may not have realized it, but he was living through the last years of two wealthy cities, Ugarit and Mycenae, that dominated the eastern Mediterranean Sea during what historians call the Bronze Age, from roughly 3000 to 1200 B.C.E.

More than a thousand years before the Greeks invented democracy and the Romans undermined it with imperialism, these city-states of the Bronze Age laid the foundations for what is often called Western civilization. Homer recorded the myths of the Bronze Age in “The Iliad” and “The Odyssey,” and carved stone inscriptions of the pharaohs Hatshepsut and Thutmose III record the machinations of the Bronze Age elites. Although the rulers of the Bronze Age sometimes went to war, the true source of their power, like that of today’s biggest cities, was economic power secured through trade. The final decades of Ugarit and Mycenae tell us a lot about why cities fail — and who survives amid the ashes.