Prince Louis Napoleon was born with a compelling sense of destiny. The eldest nephew of Bonaparte, he came from exile and ignominy to rule France, first as President then as Emperor for 22 years, from 1848 to 1870. Under his benevolent dictatorship, the nation grew in artistic fulfilment, industrial wealth and international influence - until catastrophic defeat at the hands of Bismarck in the Franco-Prussian War of 1870-71 cast her back into the shadows.