This volume is the result of a long commitment of the online journal DEP: Deportate, esuli, profughe to the themes of women pacifists’ thought and activism in the 1900s. The volume is a collection of contributions centred around three main themes. The first part, “Living War: Women’s Experiences during the War”, brings together first-hand accounts from women’s lives as they face the horrors of war, drawn mainly from original sources such as diaries, letters, memoirs and writings. The second, “Thinking Peace: Feminist Thought and Activism”, explores the lives and thought of several key women activists who challenged inequalities and sought to create new opportunities for women, contributing to the definition of a transnational culture of peace. The final section, “International Relations: Toward Future World Peace”, examines the work of a group of women who saw the outbreak of the First World War and the emergence of an international women’s movement for peace as an opportunity to act for their personal emancipation, and, in some cases, for a different idea of politics.The volume fills a notable gap in international history studies, providing a selection of contributions from little-known European contexts such as Italy, Poland, and Austria. The presence and contribution of African-American women, which has been neglected in the history of women’s pacifism, is also explored. Particular attention is given to the Women’s International League for Peace and Freedom and to the International Congress of Women, held in The Hague in 1915.