This life of Charles Darwin begins with one of the secrets of the great man's success - he was rich. Thanks to his family's wealth and position Charles never needed to worry about money, and could devote his life to his interests, an undoubted factor in his success. He made major contributions to the study of geology, he virtually invented the science of ecology and he wrote two books which changed for ever our view of life on Earth and man's place in the natural order. In an extended postscipt the author analyses the secret of Darwin's success, follows the changing fortunes of his theories according to fashions in intellectual thought, and explains his significance in the context of two centuries of evolutionary speculation and discovery.