We study the consequences of slavery in Eastern Europe, the largest source of commercial slaves in the early modern world after West Africa. Constructing the first comprehensive dataset on Eastern European slave raids, we estimate that approximately five million people were captured from more than 600 locations between the 15th and 18th centuries. Using difference-in-differences and instrumental variables strategies, we find that – unlike in Africa – local raid intensity is positively associated with a variety of long-run development outcomes. We interpret these results as reflecting an economically advantageous process of defensive state-building linked to the hostile relationship between slave raiders and local elites and the relatively large and unified nature of raided states. Our findings caution against generalizing conclusions about slavery’s consequences from the African context, suggesting that the structure of slave production plays a key role in conditioning such effects.