4 From Surviving the War Trenches to Storming the Gender Barricades? Marriage Patterns in Belgium in the Early Twentieth Century and the Impact of War on Gender Relations Saskia Hin, Paul Puschmann, and Koen Matthijs Introduction: The Impact of War on Marriage and Gender Relations Warfare profoundly affects the life courses of men, children, and women. It is less clear how war is related to (the dynamics of) gender (in)equali- ties. A survey in the early 2000s suggested that the frequency of warfare across societies correlated somewhat with cross-cultural levels of gender inequality but did so only to a modest and uneven extent. 1 Of how indi- vidual wars impact upon gender relations, we know very little, and of how war, gender relations, and marriage and family patterns influence each other, even less: so far, demographic perspectives have not played a prominent role in the historical debate. This study seeks to fill part of this gap by studying trends in first marriage patterns before, during and after World War I (WWI). Since marriage patterns are intricately linked with couple dynamics and gender relations at the micro-level, marriage certifi- cates provide us with excellent material for a bottom-up perspective on how the First World War affected gender relations. Various aspects of marriage behaviour may be understood in the light of gender dynamics and the position of men and women in the private and public domains. Large age gaps between partners may point to less equal relationships and imbalances in the bargaining power of each partner. 2 Young ages at first marriage for women have been seen as indicative of gender-separated spheres, of male (reproductive) power over women, and of a normative system in which men are seen as heads of the household, while women are valued primarily as wives and mothers. 3 In this study, we use long-term trends in ages at first marriage and age gaps between partners as an – not the – indicator of gender patterns. Second, we look at trends in social homogamy, based on the profession of partners. The