Italy's Alpine approaches formed a natural redoubt, raising the question of why Roman governments did not keep dependable troops in the mountain passes. The answer is fiscal and institutional: emperors faced unstable politics and cut costly frontier forces, weakening the barrier that protected Italy. Late Roman dependence on hired troops also created the danger of unpaid soldiers entering the political centre to demand what they were owed. The passage offers a compressed interpretation of how terrain, military finance, and state capacity can interact.
Notable Point · 1:33:54-1:35:07
How abandoning Alpine garrisons weakened Rome
An aside on Italy's mountain frontiers argues that economising on pass garrisons weakened the Roman state's defensive core.