The Peace of Constance was an agreement reached in 1183 that ended the conflict between the Holy Roman Emperor Frederick I Barbarossa and the northern Italian cities. This treaty recognized the autonomy of several cities in the region, allowing them to govern themselves while still acknowledging the emperor's authority. The peace was significant as it marked a shift in power dynamics, giving more control to local governments. It also laid the groundwork for future relations between the empire and the Italian city-states, influencing the political landscape of northern Italy for years to come.