Perfect Storms: Disasters That Changed the World season 1 episode 4
Episode title: The Lost Legion
9 A.D. Three Roman Legions are ambushed and wiped out in a remote German forest during a thunderstorm. The severed head of Roman General Varus is sent back to Rome in a box and the Roman attempt to bring Germania into the Empire is stopped dead in its tracks. The battle helps create the boundary between Latin and Germanic Europe that exists to this day.
