In 1650, the theologian and scholar Bishop James Ussher announced that the world was created on 23rd October 4004 BC. This date had been carefully calculated by adding together all the ages and reigns of the monarchs recorded in the Bible. In the late eighteenth century, James Hutton set out to prove him wrong. A gentleman farmer with legal and medical training, Hutton was fascinated by the natural landscape and in particular by rock formations. He was also surrounded by some of the most brilliant men of his day - Erasmus Darwin, Adam Smith, James Watt and David Hume. Looking at the irregular strata in the layers of the earth, Hutton deduced that the world must be much, much older than Ussher's prediction. His revelation was blasphemy - but it was also one of the most extraordinary defining moments in history, forming the framework for Darwin's theory of evolution, and shaping our modern view of the world and our place in it.