In 9 AD, the rebel chieftain Arminius and his confederation of Germanic tribes ambushed three Roman legions in the Teutoburg Forest. For days the Romans were relentlessly stalked through the woods and pounced on by their pursuers. All told, up to 20,000 Romans were killed in the chaos, and only a handful were able to escape. The battle proved to be one of Rome's most devastating defeats, and left a scar in the Roman psyche for generations to come.In this Explainer episode, Dan explores the historical context for the battle and its profound consequences for Roman strategy and expansion. He's helped by Dr. Simon Elliott, who provides deeper insights into how the Roman military worked, and where its vulnerabilities lay.Warning: this episode contains accounts of violence that some listeners may find disturbing.Written and produced by Dan Snow, and edited by Max Carrey.Sign up to History Hit for hundreds of hours of original documentaries, with a new release every week and ad-free podcasts. Sign up at https://www.historyhit.com/subscribe.