"Modernising Sexualities" is an academic book that examines the constructions of sexualities and their intersection with nation-building between the 1890s and 1930s. Through the standardization of the Swiss Penal Code, it argues that sexualities and national identity are closely intertwined. The author, Natalia Gerodetti, highlights how ideas and discourses about borders, their maintenance and reproduction in a context of national fears and concerns about degeneration influenced practices of inclusion and exclusion within the national imaginary. The book contributes to the emerging debates on gender, sexuality, and nation, linking these topics with literature on eugenics and social policy. It offers an interdisciplinary analysis of the regulation of sexuality, gender, age, and bodies by examining legal, political, medical, and everyday discourses that are employed in discussions about the regulation of sexualities.