Rulers on the road: itinerant rule in the Holy Roman Empire, AD 919–1519

Itinerant rule, rule exercised through traveling, was a common, yet insufficiently researched pre-modern form of governance. Studying the determinants of ruler itineraries in the Holy Roman Empire AD 919–1519, we argue that rulers focused on monitoring “marginal” elites. Powerful rulers could count on family members and thus targeted unrelated local elites. Weak emperors had to monitor their less loyal relatives and left unrelated nobles unvisited. We reconstruct emperors’ itineraries from 72’665 dated and geolocated documents and measure territorial control by their relatives. Exploiting the weakening of imperial power through the Great Interregnum (1250–1273), we find that strong, pre-1250 emperors frequented areas controlled by their relatives relatively less. In contrast, family control increased visits post-1273. Causal identification rests on the discontinuous reduction of emperors’ power through the Great Interregnum and differences in family relations between subsequent emperors. The results show strategic itinerant rule as an important but understudied form of governance. The data and materials required to verify the computational reproducibility of the results, procedures and analyses in this article we be available on the American Journal of Political Science Dataverse within the Harvard Dataverse Network upon publication of the article.