For 11 years after Cannae the war surged around southern Italy as cities went over to the Carthaginians or were taken by subterfuge, and the Romans recaptured them by siege or by suborning pro-Roman factions. Hannibal repeatedly defeated Roman armies, but wherever his main army was not active the Romans threatened Carthaginian-supporting towns or sought battle with Carthaginian or Carthaginian-allied detachments; frequently with success. By 207BC Hannibal had been confined to the extreme south of Italy and many of the cities and territories which had joined the Carthaginian cause had returned to their Roman allegiance.