Four Days in September examines the Battle of Teutoburg (also known as the Battle of the Teutoburg Forest), one of the most famous battles of ancient history. In late September of 9 AD, three Roman legions were attacked in a prolonged four-day battle with the Germanic barbarians, and were eventually defeated by the rebel German leader Arminius. The defeat was a crushing blow to both Rome's military and its pride. This new revised edition of Four Days in September thoroughly examines the ancient sources, looks at new facts, analyses the hypotheses of modern scholars, and puts forward hypotheses of its own in order to get the clearest picture on the dynamics of the prelude to the battle, the battle itself, and its aftermath.