An England vs Germany football match is one of the most passionate and controversial sporting events there is - whether it's a club match or an international. Here, David Downing, the acclaimed author of "Passovotchka", examines the history of such clashes. He unearths the stories, the statistics, the footballing trends, and is then able to show how events on the football field have often mirrored the cultural and political identities of the two countries. Two nations, one goal.