With Russia’s illegal annexation of Crimea and the outbreak of the Donbas war in 2014, Ukraine faced a new and shocking reality. Amid the turmoil, anxiety, and a critical shortage of resources caused by the violence, civilians swiftly mobilized to respond to urgent humanitarian and military needs. As fighting engulfed Donbas, ordinary Ukrainians came to the rescue, providing critical aid to the Ukrainian military and caring for the internally displaced. Civilian volunteer networks quickly became some of the most trusted and essential social institutions in the country. Lives Altered by War offers an in-depth analysis of these networks, explores their functioning and discusses the demographic profiles of the volunteers in three cities of Eastern and Southern Ukraine – Kharkiv, Dnipro, and Odesa. Nataliia Stepaniuk reveals how war engagement profoundly reshaped volunteers’ sense of belonging, sparking significant shifts in national attachment, community cohesion, and relations to the state. Civilian action strengthened volunteers’ allegiance to Ukraine and inspired them to radically distance themselves from Russia. It also affected their language use, gender norms, and understandings of citizenship. Drawing on fieldwork and interviews with wartime volunteers, the book brings an ethnographic lens to the study of violence and its intersections with grassroots mobilization, nation-building, and state-building from the ground up. Examining the impact of war on shared belonging, Lives Altered by War offers much-needed insight into the power of collective action and its transformative effects on individuals and communities.