William Lilly (1602–1681) produced uncannily accurate forecasts about the country’s fortunes during the Civil War and predicted the Great Fire of London. Highlighting the links between prophecy and politics in a tumultuous age, this biography describes how Lilly rose from humble farming origins to become an astrologer consulted by both King and Parliament; how he produced his prophecies and evaded efforts to silence him; and how his almanacs and astrological guidebook influenced popular culture.