Why did European rulers turn postal services into state monopolies?

European rulers transitioned postal services into state monopolies primarily to enhance the security and revenues of the state.1

During the late Middle Ages and early modern period, the rise of nation-states with strong central governments led rulers to view the control of communication networks as a strategic advantage. By establishing state-run relay posts, monarchs could ensure the reliable and secure transmission of official correspondence.1

As these systems expanded, rulers recognized the fiscal benefits of carrying private mail. Consequently, they legalized and integrated private correspondence into their networks, often suppressing or buying out private competitors to consolidate their control. This evolution allowed governments to combine improved public service with increased profitability, effectively turning the postal system into a state-managed enterprise. While private enterprises occasionally introduced innovations—such as local urban delivery services—these were frequently absorbed by the state to maintain the integrity of the monopoly.1