Nation-building efforts, that is policies aimed at "forming countries in which citizens feel a sufficient amount of commonality" (Alesina and Reich, 2015), can have positive economic and political effects. Societies with less ethnic, linguistic or religious cleavages are less prone to political instability and exhibit more economic growth (Alesina et al. 1999; Miguel, 2004). However, we still know very little about which policies or mix of policies are efficient to spread a common identity. One of such tool, often pushed forward by media, is the role of "charismatic leaders", that is specific individuals able to coordinate groups or embody themselves a larger common identity. Prominent actions by leaders, including speeches, could also constitute emotionally charged experiences that help build the "imagined communities" that are nations (Anderson, 1983). To the best of my knowledge, there is however no empirical test of these hypotheses. The goal of the project is to fill this gap and answer the following question: Can leaders successfully shape social norms by forging a common identity? I do so by studying the role of Mustafa Kemal, the founder of modern Turkey, in spreading a new national identity. I use time and geographic variation in Kemal’s visits to cities, in a difference-in-differences design, to test whether direct exposure to a charismatic leader causally affects citizens’ take-up of the new national identity. I create a new database using various historical sources, with detailed information on his travels, and cities and district characteristics. I proxy adherence to the new Turkish identity by the adoption of first names in "Pure Turkish", the new language introduced by the state. I find that cities visited are more likely to adopt first names in the new language. The effect is quite persistent, consistent with the Weberian view that charismatic authority can play a role in legitimizing new social orders. I also find that Kemal was more efficient in spreading a new identity compared to Ismet Inonu, his second man, suggesting that he did not only have a pure informational effect. I am currently digitizing additional archives to study his differential effect depending on local characteristics (ethnic and linguistic fractionalization, repression of minorities) and to understand whether he was a complement or substitute to other nation-building tools (such as education, local political clubs or railroad expansion). This project constitutes the first quantitative evaluation of the short and long term effects of nation-building efforts in the region.