How did the idea of popular sovereignty contribute to nationalism?

The idea of popular sovereignty was a fundamental catalyst for the development of modern nationalism, as it fundamentally shifted the source of political legitimacy from the monarch to the people.12

By the 18th century, the rise of popular sovereignty—the principle that government is created by and subject to the will of the people—transformed the state into a "national state" or "fatherland". This shift had several key effects:13

• Replacement of the Monarch: Under the influence of thinkers like John Locke and Jean-Jacques Rousseau, the people replaced the king as the center of the nation. The state was no longer identified with the ruler but with the community of citizens.132
• National Sovereignty: Popular sovereignty provided the moral-philosophical foundation for national sovereignty, which recognizes the right of a national community to govern itself. This fused the state with the nation, creating the nation-state as a polity ruled in the name of a specific people.2
• Political Mobilization: The French Revolution demonstrated how these liberationist principles could unify a population, sweeping away feudal privileges and fostering a shared national identity that transcended local or aristocratic allegiances.45