The Introduction first provides an overview of concubinage in Chinese history. It then traces the rise of modern social women in Republican China, a significant historical development that contributed to shaping the stories told in this book. Next, it focuses on the institution of concubinage in Republican China, analyzing three broad and intertwined developments that serve as the larger context for the case studies in this book: (1) The increasing social stigmatization of the concubine and the rise of her domestic status; (2) the emergence of modern-educated concubines and their active but controversial public presence; and (3) the democratization of concubinage and the emergence of the Anti-Concubinage Movement. Although some scholars have noted these changes, none have connected these issues and given them concentrated treatment, investigating the broader impact of concubines’ public presence on the society, culture, and gender politics of Republican China. This book weaves these trends together to present a new picture of an important phenomenon and its implications for modern Chinese history. Finally, it introduces the sources, methodology, and structure of the book.