28 June 1914 and April 1945. The Story Behind two pistol shots: the single bullet, fired by a young Serb nationalist that triggered World War 1 and the self-administered shot that brought about the end of Adolf Hitler and World War 2.

4 April 1968 and February 1990. How two men - both intellectuals and determined opposers of racial oppression - came to symbolise the fight for equality as their lives for their cause.

This episode dramatises the minute by minute events leading up to the world's first ever atomic bombing. Based on extracts from President Truman's personal diaries which show the decision-making process reflecting America's real fear that the Japanese would never give up, Japanese eyewitness accounts of the tragedy in Hiroshima, diaries written on board Enola Gay, and the personal testimony of Colonel Paul Tibbets, the man who led the mission so secret not even his crew knew the enormity of what they were doing.

17 July 1918 and 9 November 1989. The Murder of the Russian royal family marked Russia's irrevocable move from a monarchy to a Communist state. Seventy Years later, the fall of the Berlin Wall symbolised the collapse of the ideology.

9 November 1938 and 14 May 1948. Just ten years after the Nazis openly attacked Jews and their property - a huge step on the nightmare spiral to the Holocaust, the 2000 year old dream of a Jewish homeland becomes a reality and the state of Israel is Born.

26 November 1922 and 17 September 1822. Two days that brought ancient Egypt dramatically to life. In 1822, Jean-Francois champollion cracks Egyptian hieroglyphs. One hundred years later, Howard Carter reads the name on a tomb and makes an amazing discovery.

2 December 1942 and 26 April 1986. The first controlled nuclear chain reaction heralded the atomic age, but Chernobyl's runaway chain reaction was the first warning. How did the most exciting scientific breakthroughs ever lead to the disaster that the world had dreaded?