Resumen: Populations are affected by shocks of different kinds, and wars, a priori, may be among the most prominent. This article studies the effect of the Spanish Civil War (1936–1939) shock on the distribution of population, especially on cities. One of the main contributions of this study is that it underlines the importance of distinguishing between winning and losing sides, an aspect which until now has been largely overlooked. While previous research on war shocks has also tended to be concerned with inter-state wars, this paper concentrates on a civil war. We take advantage of a new, long-term, annual data set. Our results show that, overall, the Spanish Civil War did not have a significant effect on city growth. However, we also find a significant and negative effect in the growth of cities that aligned themselves with the losing side. These results are robust to heterogeneity in the effect of the war shock, measured as war severity and duration. Although short lived, the temporary effect on growth results in a permanent effect on the size of cities on the losing side. Idioma: Inglés DOI: 10.1111/jors.12643 Año: 2023 Publicado en: JOURNAL OF REGIONAL SCIENCE 63, 4 (2023), 898-921 ISSN: 0022-4146 Factor impacto JCR: 3.2 (2023) Categ. JCR: ECONOMICS rank: 108 / 600 = 0.18 (2023) - Q1 - T1 Categ. JCR: REGIONAL & URBAN PLANNING rank: 14 / 54 = 0.259 (2023) - Q2 - T1 Categ. JCR: ENVIRONMENTAL STUDIES rank: 68 / 182 = 0.374 (2023) - Q2 - T2 Factor impacto CITESCORE: 4.9 - Development (Q1) - Environmental Science (miscellaneous) (Q2)