By the end of the fourth century BCE, the Romans had probably not far short of half a million troops available (compare the 50,000 or so soldiers under Alexander in his eastern campaigns, or perhaps 100,000 when the Persians invaded Greece in 481 BCE). This made them close to invincible in Italy: they might lose a battle, but not a war. Or as one Roman poet put it in the 130s BCE, ‘The Roman people has often been defeated by force and overcome in many battles, but never in an actual war on which everything depends.’
