Empire of the Summer Moon is a historical book by S.C. Gwynne that tells the story of the Comanches, the most powerful Native American tribe in American history, and their conflict with white settlers for control of the American West. The book also focuses on the life of Quanah Parker, the son of a Comanche chief and a white captive, who became the last and greatest leader of the Comanches. The book is based on extensive research and vividly portrays the culture, warfare, and legacy of the Comanches.