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Events on Saturday 25 June 1183 1
1183Treaty of ConstanceFrederick Barbarossa makes peace with the Lombard LeagueHoly Roman Emperor Frederick I and the cities of the Lombard League signed a peace ending decades of conflict over imperial authority in northern Italy. The treaty confirmed the cities' rights to self-government, fortification, and local jurisdiction while preserving nominal imperial overlordship. It stabilized northern Italy and set a model for city-state autonomy within the empire.