We study how more negative historical exposure to the actions of nation-states—like war, occupation, and repression—affects the formation of regional identity. The quasi-exogenous division of the French regions Alsace and Lorraine allows us to implement a geographical regression discontinuity design at the municipal level. Using measures of stated and revealed preferences, we find that more negative experiences with nation-states are associated with a stronger regional identity in the short, medium, and long run. This is linked to preferences for more regional decision-making. Establishing regional organizations seems to be a key mechanism to maintaining and strengthening regional identity. (JEL H77, N43, N44, N93, N94, Z13)