Since Homer's Iliad was written 3,000 years ago, generations have been enchanted by the tale of the beautiful Helen, impetuous Achilles and mighty Agamemnon - and, of course the horse. But could there be truth in the legend? Since 1988, Professor Manfred Korfmann has been excavating the site of Troy. He has discovered how large the city was, how well it was defended and, crucially, that there was once a great battle there at precisely the time experts believe the Trojan War occurred. But who attacked the city, and why?