Professor Saul David uses the BBC archive to chart the history of the world's most destructive war, by chronicling how the story of the battle has changed. As new information has come to light, and forgotten stories are remembered, the history of World War Two evolves. The BBC has followed that evolution, and this programme examines the most important stories, and how our understanding of them has been re-defined since the war ended over 70 years ago.

At the outbreak of war in 1939, wondering whether Russia would join the fight with the Allies, Sir Winston Churchill famously described this nation as 'a riddle wrapped in a mystery inside an enigma'. These words have almost come to define Britain's view of Russia ever since; an inscrutable power that always plays by its own rules.

Military historian Saul David draws on classic Timewatch documentaries and a wide range of BBC archive to examine how television has portrayed Russia through the years. From our trusted World War II ally to the red oppressor of the Cold War, from a potential free-market friend when Communism crumbled to a new 21st-century foe under Putin, Russia has swung from friend to foe and back again - either way, we find it incredibly hard to understand her.

This programme explores how arguably Britain's most complex international relationship has played out on television.