The disappearance of Rome's Ninth Legion has long baffled historians, but could a brutal ambush have been the event that forged the England-Scotland border, asks archaeologist Dr Miles Russell.One of the most enduring legends of Roman Britain concerns the disappearance of the Ninth Legion. The theory that 5,000 of Rome's finest soldiers were lost in the swirling mists of Caledonia, as they marched north to put down a rebellion, forms the basis of a new film, The Eagle, but how much of it is true? > Hadrian's Wall was designed to keep invaders out of Roman territory as well ensuring...