Alexander von Humboldt (1769-1859) is the great lost scientist: more things are named after him than anyone else including towns, rivers, mountain ranges, a penguin, a giant squid - even the Mare Humboldtianum on the moon. His colourful adventures read like something from Boy's Own: Humboldt explored deep into the rainforest, climbed the world's highest volcanoes and inspired princes and presidents, scientists and poets. Taking us on a fantastic voyage in his footsteps, Andrea Wulf shows why his life and ideas remain so important today.