When Alexander the Great carved out his empire, Rome was just one of many city states on the Italian peninsula. Yet it conquered its neighbours one-by-one, defeated Carthage and eventually overwhelmed the Greek successor states too. As its republican institutions gave way to Imperial rule by Augustus and his heirs, the Roman Empire extended from the French Atlantic coast to Syria. Later conquests included Britain and much of modern Romania. How did Rome overcome opponent after opponent? What was the grand strategy of the Roman Empire? Adrian Goldsworthy reveals why Rome developed the most professional fighting force of the ancient world and what it was like to be a soldier in the legions.