This chapter aims to understand the impact of the First World War on marriages and divorces and eventually on gender relations in France. It first discusses how women responded to the shortage of marriageable men by adapting their partner choices: they more frequently established unions with widowed or divorced men, and with foreigners, as well as with younger or older men rather than men of their own age. These ‘compensatory marriages’ led to a decrease in men’s celibacy, and thereby limited the impact of the war on marriage rates. The second part of the chapter focuses on trends in and the characteristics of divorces to understand the consequences of the war on couples that had been separated during the conflict, but also to know whether compensatory marriages faced a greater risk at divorce than other marriages. We show the impact of the first-world conflict on young couples and their families, who did not always manage to withstand the separations and the physical and psychological consequences of the war on soldiers. This held true especially for the cohorts of soldiers who were in their thirties during the conflict, and who were often married, or even fathers.