How do you sustain a city of 1.2 million people in an age of ox-carts and sailing ships? Most history focuses on Caesar’s battles or Nero’s madness. But the true miracle of Rome wasn't its army—it was its logistics. In this episode of The Mechanisms of Power, we reverse-engineer the Annona, the invisible administrative machine that prevented Rome from starving for five centuries. Rome's local hinterland could only feed 20% of its population. To solve this, the Roman state built the most sophisticated pre-industrial supply chain in history, moving 400,000 tons of grain annually across 2,000 kilometers of open sea. We dissect the system's hardware: Procurement: How Rome used tax-in-kind to turn Egypt and North Africa into imperial fuel tanks. The Fleet: The 400-ship "lifeline" and the state insurance schemes that kept merchants sailing in winter. I ...