On an East-African hunting expedition in 1909, Delia Akeley, a forty-year-old American woman, captured a baby female monkey. Delia's loneliness in an isolating patriarchal world, and her long-frustrated desire to adopt a child, had motivated her to nurture the animal. She named the monkey JT Jr and decided to study her interactions with humans. The unique relationship between Delia and JT unlocked Delia's latent talents of research and observation, anticipating both Jane Goodall's chimpanzee writings and Margaret Mead's Samoan ethnographies. However, Delia's love for JT clashed with her husband Carl's obsession to create a temple of African wildlife dioramas at the Museum of Natural History in New York. Nursing Carl's broken body and realising their diverging interests pushed Delia into a breakdown in Uganda, which led to a savage divorce in Manhattan, and the heartbreaking caging of JT in a Washington zoo. Carl's death triggered a long battle between Delia and Carl's widow, who succeeded in obliterating most of Delia's achievements. In Delia Akeley and the Monkey, Iain McCalman uses official records and personal documents to build a story of passionate love and hate among women, men, animals and museums that predates our times but speaks to our present. It illuminates much about human–animal relations and the tyranny of gender inequality, through reinstating an obscured story of a dedicated amateur primatologist.