Rome's Greatest Defeat: Massacre in the Teutoburg ForestOver four days at the beginning of September AD 9, half of Rome's Western army was ambushed in a German forest and annihilated. Three legions, three cavalry units and six auxiliary regimentssome 25,000 menwere wiped out. It dealt a body blow to the empire's imperial pretensions and was Rome's greatest defeat. No other battle stopped the Roman empire dead in its tracks. From the moment of the Teutoburg Forest disaster, the Rhine, rather than the Elbe