In the final part of the series Bettany Hughes recalls the time that marked Rome's symbolic break with its 1,000-year pagan past - the day in 337AD that Emperor Constantine the Great was baptised a Christian. It was a moment of profound significance not just for the empire, but for the history of the world and one of its major religions. Constantine was one of the last great Roman emperors to rule over a united empire, giving it a new capital - Constantinople, today known as Istanbul - a city which would one day eclipse Rome as the greatest city on Earth.
Japanese General, Hideki Tojo is a cold blooded control freak, who takes millions to their deaths in the dirtiest war ever known. This is the story of the dictator responsible for Pearl Harbor, an Asian Holocaust and the torture of thousands of POWs.
Europe has never experienced such a long period of peace and prosperity as after the Second World War. When the Iron Curtain fell in 1989, the dream of a Europe united in peace and freedom seemed to have finally to become a reality. But the clouds of nationalism have started to gather once again.
What happened when early humans ventured out of Africa and into Asia? Where did they go and whom did they meet along the way? The latest evidence suggests they left far earlier than previously thought and interbred with other types of ancient human - Homo erectus, Neanderthals and also the Denisovans, whose existence was established only five years ago when geneticists extracted DNA from a tiny fragment of finger bone. Because these ancient humans mated with our ancestors, their genes have found a home in our DNA. More than that, they’ve helped us survive and thrive.
Mankind takes on godlike powers: to feed billions of people, reshape the landscape, re-engineer the human body. The greatest power of all was unleashed over Hiroshima on 6 August 1945. Since entering the Atomic Age we’ve been living between eternity and oblivion. But at the same time, we’ve become more connected as a species. 100,000 years ago there were a few thousand hunter-gatherers on the African savannah. Today there are 7 billion of us in every corner of the globe. It’s been an amazing journey.