One of the most profound and lasting effects of the Crisis of the Third Century was the disruption of Rome's extensive internal trade network. Ever since the Pax Romana, starting with Augustus, the empire's economy had depended in large part on trade between Mediterranean ports and across the extensive road systems to the Empire's interior. Merchants could travel from one end of the empire to the other in relative safety within a few weeks, moving agricultural goods produced in the provinces to the cities, and manufactured goods produced by the great cities of the East to the more rural provinces.