This is the story the Great Mansions of the Highgate Ridge, and the visionaries who lived in them. Using seldom seen material from the HLSI archives, the lecture focuses on the lifestyles of the early owners of these houses and the pioneering reforms for which many of them fought. Now that London has because a location of choice for the global rich, the lecture considers what we can learn from the similarities and differences between the lifestyles of the new occupiers of these mansions and those who lived in them a hundred years ago.