Michael Portillo revisits great moments of history to discover that they often conceal other events of equal, but forgotten, importance. This week he looks at forgotten aspects of the 1936 Berlin Olympics . Did Adolf Hitler really snub Jesse Owens after the American athlete won an unprecedented four gold medals ? What have we forgotten about the efforts made in Britain and the United States to boycott the Games and why weren't those efforts successful ? And what do the Games tell us about the uneasy relationship between sport and politics in the years before the outbreak of war.