Abstract
This article explores the impact of the postal system on the consolidation of state authority in pre-modern Europe. Previous research indicates that geographical scale limits the state's ability to rule directly in this period. I argue that European states used the post to mitigate this constraint. Posts substantially reduced communications cost so that they became a crucial infrastructure of delivering information. I investigate the effect of postal service on the state's authority with a new data set on France. Using the persistence of non-French speakers as my outcome variable, I show that geographical distance from the capital reinforces the persistence, but postal expansion mitigates this challenge. I address the endogeneity concern that postal development is determined by resistance from minority people through two additional analyses: the first focuses on the impact of the post interacted with certain distances from Paris and the second incorporates factors outside France.