Emma Williams (1765-1815) was the daughter of a poor village blacksmith, but she never permitted her lowly beginnings to thwart her ambitions. By the time she was 17, she was already a fixture in London society, having graduated from a brothel into the arms of several mistress keepers. After a succession of lovers, she married the aging Sir William Hamilton, the British envoy to Naples. She enriched her husband's Italian portfolio by charming King Ferdinand I, Queen Maria Carolina, Wolfgang von Goethe, and others before she fixed her magic on Napoleonic War hero Lord Horatio Nelson. Her relationship with him (which produced a child) ensured her fame and sealed her doom. This biography, the first in 20 years, redeems the reputation of "England's mistress."