The First World War claimed a life every twenty-five seconds. What was the point of it all? Surely, all the grief and loss would spawn a new world order, one in which peace and prosperity would replace inequality, injustice and dynastic swagger. But twenty years after the guns fell silent, war broke out again. Why did the peace that people prayed and died for last little more than twenty years? How did tyrants rise to control the fate of continents? Two world wars tore the heart out of the twentieth century. Between these two tragedies, the world lit up with jazz, the talkies, radio and the motor car. This age of light was, in fact, an age of anxiety.